Consider the function shown.
Which of the following could be the equation of this function?
- \(y=2 x+3\)
- \(y=2 x-3\)
- \(y=-2 x+3\)
- \(y=-2 x-3\)
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Consider the function shown.
Which of the following could be the equation of this function?
\(C\)
\(\text {Gradient is negative (top left } \rightarrow \text { bottom right)}\)
\(y \text{-intercept = 3 (only positive option)}\)
\(\Rightarrow C\)
Which of the following could be the graph of `y= –2 x+2`?
`A`
`text{By elimination:}`
`y text{-intercept = 2 → Eliminate}\ B and C`
`text{Gradient is negative → Eliminate}\ D`
`=>A`
Which of the following best represents the graph of `y = -3x + 4`?
| A. | B. | ||
| C. | D. |
`A`
`y = -3x + 4`
`ytext(-intercept) = 4`
`text(Gradient is negative → slopes from)`
`text(upper left to lower right)`
`=> A`
Suppose `y = -1-2x`.
When the value of `x` increases by 5, the value of `y` decreases by
`D`
`text(Strategy 1)`
`text(If) \ \ x\ \ text(increases by) \ 5`
`=> y \ \ text(decreases by) \ \ 2x = 2 xx 5 = 10`
`text(Strategy 2)`
`text(Test) \ 2 \ text(values:)`
`text(If) \ \ x = 0 , \ y = -1`
`text(If) \ \ x = 5 , \ y = -1-10 = -11`
`:.\ y \ text(decreases by) \ 10.`
`=>D`
Which of these equations represents the line in the graph?
`A`
`text{Graph passes through (0, 11) and (5.5, 0)}`
| `text(Gradient)` | `=(y_2-y_1)/(x_2-x_1)` | |
| `=(11-0)/(0-5.5)` | ||
| `=-2` |
`:.\ text(Equation is:)\ \ y = 11 – 2x`
`=> A`
Leo drew a straight line through the points (0, 5) and (3, -2) as shown in the diagram below.
What is the gradient of the line that Leo drew?
`D`
`text{Line passes through (0, 5) and (3, – 2)}`
| `text(Gradient)` | `= (y_2-y_1)/(x_2-x_1)` |
| `= (5-(-2))/(0-3)` | |
| `= -7/3` |
`=>D`
Renee went bike riding on a holiday.
The hiring charges are listed in the table below:
\begin{array} {|l|c|c|}
\hline \text{Hours hired} \ (h) & 1 & 2 & 3 & 4 & 5 \\
\hline \text{Cost} \ (C) & 18 & 24 & 30 & 36 & 42 \\
\hline \end{array}
Which linear equation shows the relationship between `C` and `h`?
`A`
`text(Consider Option 1:)`
`12 + (6 xx 1) = 12+6=18`
`12 + (6 xx 2) = 12+12=24`
`12 + (6 xx 3) = 12+18=30\ \ \ \ text(etc …)`
`:.\ text(The linear equation is:)\ \ C = 12 + 6h`
`=>A`
What is the gradient of the line `2x + 3y + 4 = 0`?
`A`
| `2x + 3y + 4` | `= 0` |
| `3y` | `= -2x – 4` |
| `y` | `= -2/3 x – 4/3` |
| `:.\ text(Gradient)` | `= -2/3` |
`=> A`
What is the slope of the line with equation `5x+2y-8 = 0`?
`A`
| `5x+2y-8` | `= 0` |
| `2y` | `= -5x+8` |
| `y` | `= -5/2 x+4` |
`:.\ text(Slope)\ = -5/2`
`=>A`
Sketch the graph of `y - 2x = 3`, showing the intercepts on both axes. (2 marks)
--- 8 WORK AREA LINES (style=lined) ---
`y-2x=3\ \ => \ \ y=2x+3`
The graph shows a line which has an equation in the form `y = mx + c`.
Which of the following statements is true?
`=> A`
`m` is the gradient and the line slopes to the right so `m` is positive.
`c` is the `y`-intercept which is negative.
`:.\ m` is positive and `c` is negative.
`=> A`
`A`
`l\ text{passes through (0, 2) and (1, 0)}`
| `text(Gradient)` | `= (y_2-y_1)/(x_2-x_1)` |
| `= (0-2)/(1-0)` | |
| `= -2` |
`y\ text(intercept = 2)`
`:.y = -2x + 2`
`=>A`
The total cost, `$C`, of a school excursion is given by `C = 2n + 5`, where `n` is the number of students.
If three extra students go on the excursion, by how much does the total cost increase?
`A`
`C = 2n + 5`
`text(If)\ n\ text(increases to)\ n + 3`
| `C` | `= 2(n + 3) + 5` |
| `= 2n + 6 + 5` | |
| `= 2n + 11` |
`:.\ text(Total cost increases by $6)`
`=> A`
Which equation represents the relationship between `x` and `y` in this table?
`D`
`text{By elimination (using the table)}`
`(0, 1)\ text(must satisfy)`
`:.\ text(NOT)\ B\ text(or)\ C`
`(2, 2)\ text(must satisfy)`
`:.\ text(NOT)\ A`
`=> D`
`D`
`y = 2x-2`
`text(By elimination)`
`text(It has a)\ y\ text(intercept of)\ -2`
`=> text(Cannot be)\ B\ text(or)\ C`
`(-1, 0)text{ from}\ A\ text(doesn’t satisfy equation)`
`text(but)\ (1,0)\ text(from)\ D\ text(does)`
`=> D`
If `A = 6x + 10`, and `x` is increased by 2, what will be the corresponding increase in `A` ?
`D`
`A = 6x + 10`
`text(If)\ x\ text(increases by 2)`
`A\ text(increases by)\ 6 xx 2 = 12`
`=> D`