If \(\large x\) is a negative number, which of the following is true?
- \(x+2\) is always negative.
- \(x\times -1\) is always negative.
- \(2-x\) is always negative.
- \(x-2\) is always negative.
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If \(\large x\) is a negative number, which of the following is true?
\(D\)
\(\text{Considering the options}\)
\(\text{Option 1: If}\ x\ge -2\ \text{then}\ x+2\ge 0, \therefore \text{not always negative}\)
\(\text{Option 2:}\ x\ \text{is negative }\therefore x\times -1\ \text{is always positive}\)
\(\text{Option 3:}\ x\ \text{is negative }\therefore 2-x\ \text{is always positive}\)
\(\text{Option 4:}\ x\ \text{is negative }\therefore x-2\ \text{is always negative}\)
\(\Rightarrow D\)
A triangle has a base of length \(3\) metres and a perpendicular height of \(h\) metres.
Write an expression for the area of the triangle. (2 marks)
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\(\dfrac{3h}{2}\ \text{m}^2\)
\(\text{Area}\)
\(=\dfrac{1}{2}\times \text{base}\times\text{perpendicular height}\)
\(=\dfrac{1}{2}\times 3\times h\)
\(=\dfrac{1}{2}\times 3h\)
\(=\dfrac{3h}{2}\ \text{m}^2\)
A rectangle has sides of \(b\) metres and \(c\) metres in length.
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a. \((2b+2c)\ \text{m}\)
b. \(bc\ \text{m}^2\)
a. \(\text{Perimeter}\)
\(=b+c+b+c\)
\(=(2b+2c)\ \text{m}\)
b. \(\text{Area}\)
\(=\text{length}\times\text{width}\)
\(=b\times c\)
\(=bc\ \text{m}^2\)
A square has sides \(x\) centimetres in length.
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a. \(4x\ \text{cm}\)
b. \(x^2\ \text{cm}^2\)
a. \(\text{Perimeter}\)
\(=4\times x\)
\(=4x\ \text{cm}\)
b. \(\text{Area}\)
\(=\text{side}^2\)
\(=x^2\ \text{cm}^2\)
At the local markets mangoes cost \($x\) and oranges cost \($y\).
Benji bought 6 mangoes and 5 oranges. Write an expression for the total cost of Benji's mangoes and oranges. (2 marks)
\(6x+5y\)
\(\text{Total cost}\)
\(=6\times x +5\times y\)
\(=6x+5y\)
Juan bought 8 identical Christmas presents online for his relatives.
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ii. Write an expression for the total reduced price of all 8 presents. (2 marks)
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a. \(8y\)
b. i. \(y-10\)
ii. \(8(y-10)\)
a. \(\text{Price}=8\times y=8y\)
b. i. \(\text{Reduced Price per present}=y-10\)
ii. \(\text{Total Reduced Price}=8\times (y-10)=8(y-10)\)
Rachel works as a waiter and is paid $27 per hour.
Write an expression for her wages in a week where she works \(x\) hours. (1 mark)
\($27x\)
\(\text{Wages} = 27\times x =$27x\)
Describe the expression \(\dfrac{5}{3q}\) in words. (2 marks)
\(\text{The quotient of 5 and }3q\)
\(\text{The quotient of 5 and }3q\)
Describe the expression \((x-y)\times 2\) in words. (2 marks)
\(\text{Twice the difference between }x\ \text{and }y\)
\(\text{Twice the difference between }x\ \text{and }y\)
Describe the expression \(3y+4\) in words. (2 marks)
\(\text{The sum of 4 and the product of }3\ \text{and }y\)
\(\text{The sum of 4 and the product of }3\ \text{and }y\)
Write an expression for subtracting half of \(x^2\) from the product of \(3\) and \(y\). (2 marks)
\(3y-\dfrac{x^2}{2}\)
\(\text{Half of }\ x^2=\dfrac{x^2}{2}\ \text{and product }3\ \text{and }y=3y\)
\(\therefore\ \text{Subtraction}=3y-\dfrac{x^2}{2}\)
Write an expression for one-third of \(m\) added to one-fifth of \(2n\). (2 marks)
\(\dfrac{m}{3}+\dfrac{2n}{5}\)
\(\text{One-third of }\ m=\dfrac{m}{3}\ \text{and one-fifth of }2n=\dfrac{2n}{5}\)
\(\therefore\ \text{Added together}=\dfrac{m}{3}+\dfrac{2n}{5}\)
Write an expression for the quotient of \(2x\) and \(z^2\). (1 mark)
\(\dfrac{2x}{z^2}\ \text{ or}\ \ 2x÷z^2\)
\(\text{Quotient means divide }\)
\(\therefore\ \text{quotient of}\ 2x\ \text{and}\ z^2=\dfrac{2x}{z^2}\ \text{ or}\ \ 2x÷z^2\)
Write an expression for 2 added to one-third of \(x\). (1 mark)
\(2+\dfrac{x}{3}\ \text{or}\ \ 2+\dfrac{1}{3}x\)
\(\text{One-third of }x =\dfrac{x}{3}\ \text{or}\ \ \dfrac{1}{3}x \)
\(\therefore\ \text{2 added}=2+\dfrac{x}{3}\ \text{or}\ \ 2+\dfrac{1}{3}x\)
Write an expression for a quarter of the sum of \(5x\) and \(4y\). (1 mark)
\(\dfrac{5x+4y}{4}\ \text{ or }\ \dfrac{1}{4}(5x+4y)\)
\(\text{Sum of }5x \text{ and}\ 4y=5x+4y\)
\(\therefore\ \text{a quarter of the sum}=\dfrac{5x+4y}{4}\ \text{ or }\ \dfrac{1}{4}(5x+4y)\)
Write an expression for double the sum of \(a\) and \(b\). (1 mark)
\(2\times(a+b)\ \text{or } 2(a+b)\)
\(\text{Sum of }a \text{ and}\ b=a+b\)
\(\therefore\ \text{double the sum}=2\times(a+b) \ \text{or }2(a+b)\)
Write an expression for the product of \(3\large xy\) and \(-\large y\). (1 mark)
\(-3\large xy^2\)
\(\text{Product means multiply}\)
\(\therefore\ 3xy\times(-y)=-3xy^2\)
Write an expression for the product of \(4\large x\) and \(\large y\). (1 mark)
\(4\large xy\)
\(\text{Product means multiply}\)
\(\therefore\ \text{product of } 4x\) \(\text{and }y=4x\times y=4xy\)
Write an expression for the sum of \(-1\) and half of \(\large m\). (1 mark)
\(-1+\dfrac{m}{2}\ \ \text{or }\ \dfrac{m}{2}-1\)
\(\text{Sum means add}\)
\(\therefore\ \text{sum of } -1\ \text{and half of } m\ = -1+\dfrac{m}{2}\ \ \text{or }\ \dfrac{m}{2}-1\)
Write an expression for the sum of 5 and 3 lots of \(v\). (1 mark)
\(5+3v\)
\(\text{Sum means add}\)
\(\therefore\ \text{the sum of 5 and 3 lots of } \ v\rightarrow 5 +3v\)
State the coefficient of \(\large y\) in the expression \(2y^3-4y^2+12xy+5y-7\). (1 mark)
\(5\)
\(\text{A coefficient is the number in front of a pronumeral}\)
\(\therefore 5 \text{ is the coefficient of}\ \large y\)
State the coefficient of \(\large c\) in the expression \(2ab+3b^2-7bc-4c+8\). (1 mark)
\(-4\)
\(\text{A coefficient is the number in front of a pronumeral}\)
\(\therefore -4 \text{ is the coefficient of}\ \large c\)
Which of the following expressions is equivalent to the quotient of \(t+8\ \) and \(3\)?
\(A\)
\(\text{Quotient means to divide}\)
\(\therefore\ \dfrac{t+8}{3} \text{ is equivalent to the quotient of }\ t+8\text{ and }3\)
\(\Rightarrow A\)
Which of the following expressions is equivalent to the quotient of \(2w\) and \(7\)?
\(D\)
\(\text{Quotient means to divide}\)
\(\therefore\ \dfrac{2w}{7} \text{ is equivalent to the quotient of } 2w\text{ and }7\)
\(\Rightarrow D\)
Which of the following expressions is equivalent to the product of \(x, y\) and \(z\)?
\(C\)
\(\text{Product means to multiply}\)
\(\therefore\ xyz \text{ is equivalent to the product of } x, y\text{ and }z\)
\(\Rightarrow C\)
Which of the following expressions is equivalent to the product of \(8m\) and \(-2\)?
\(C\)
\(\text{Product means to multiply}\)
\(\therefore\ -16m \text{ is equivalent to the product of } 8m\text{ and }-2\)
\(\Rightarrow C\)
Which of the following expressions is equivalent to the difference between \(3y\) and \(4\)?
\(B\)
\(\text{Difference means to subtract}\)
\(\therefore\ 3y-4 \text{ is equivalent to the difference between } 3y\text{ and }4\)
\(\Rightarrow B\)
Which of the following expressions is equivalent to the difference between \(\large x\) and \(10\)?
\(D\)
\(\text{Difference means to subtract}\)
\(\therefore\ \large x\)\(-10\ \text{is equivalent to the difference between } \large x\)\(\text{ and }10\)
\(\Rightarrow D\)
Which of the following expressions is equivalent to the sum of \(-5\) and \(2x\)?
\(A\)
\(\text{Sum means to add}\)
\(\therefore\ 2x-5\ \text{is equivalent to the sum of } -5\ \text{and}\ 2x\)
\(\Rightarrow A\)
Which of the following expressions is equivalent to the sum of \(3x\) and \(4\)?
\(B\)
\(\text{Sum means to add}\)
\(\therefore\ 4+3x\ \text{is equivalent to the sum of } 3x\ \text{and}\ 4\)
\(\Rightarrow B\)