The value of `6t^2` when `t = –4` is
`– 96` | `– 48` | `96` | `576` |
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Aussie Maths & Science Teachers: Save your time with SmarterEd
The value of `6t^2` when `t = –4` is
`– 96` | `– 48` | `96` | `576` |
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`96`
`text(When)\ \ t = -4,`
`6t^2` | `= 6 (-4)^2` |
`= 6 xx 16` | |
`= 96` |
A rule for `y` in terms of `x` is `y = 4 - 6x`.
When `x = 2.75` the value of `y` is
`−16.5` | `−12.5` | `−4.5` | `16.5` |
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`−12.5`
`y` | `= 4 – 6 xx 2.75` |
`= 4 – 16.5` | |
`= −12.5` |
Here is a table of values for `x` and `y`.
Which of these is a correct rule for `y` in terms of `x`?
`y = x` | `y = 2x` | `y = 6x` | `y = 4x^2` |
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`y = 4x^2`
`text(By trial and error for each given equation:)`
`text(Consider)\ \ y=4x^2,`
`0=4xx 0^2=0`
`1=4 xx 0.5^2 = 1`
`4=4xx1^2=4\ \ text(etc …)`
`:. y = 4x^2\ \ text(is the correct rule.)`
When `p = 3` and `q = –3`, what is the value of `p^2 + q^2`?
`p^2 + q^2 =` |
`18`
`p^2 + q^2` | `= 3^2 + (-3)^2` |
`= 9 + 9` | |
`= 18` |
If `x = 5`, what is the value of `(3x)/(2x - 5)`?
`2` | `3` | `4` | `15` |
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`3`
`text(If)\ \ x = 5,`
`(3x)/(2x – 5)` | `= (3 xx 5)/((2 xx 5) – 5)` |
`= 15/5` | |
`= 3` |
If `p = 7`, what is the value of `2p`?
`14` | `27` | `49` | `98` |
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`14`
`p` | `= 7` |
`2p` | `= 2 xx 7` |
`= 14` |
What is the value of `6 + 2x - x^2` when `x = −3`?
`−9` | `3` | `9` | `21` |
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`−9`
`6 + 2x – x^2` | `= 6 + 2(−3) – (−3)^2` |
`= 6 – 6 – 9` | |
`= −9` |
Ice cream is put into a waffle cone so it fills the cone to the top.
The volume, `V`, of the cone is given by the rule `V = (pir^2h)/3`,
where `r` is the radius of the cone in centimetres and `h` is the height in centimetres.
When `h = 12` and `r = 3`, the volume of the cone is closest to
`38\ text(cm)³` | `113\ text(cm)³` | `339\ text(cm)³` | `452\ text(cm)³` |
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`113\ text(cm)³`
`V` | `= (pi xx 3^2 xx 12)/3` |
`= 113.097…\ text(cm)³` | |
`=113\ text{cm³ (nearest cm³)}` |
Renee went bike riding on a holiday.
The hiring charges are listed in the table below:
Which rule shows the relationship between `C` and `h`?
`C = 12 + 6h` | `C = 6 + 12h` | `C = 18 + 12h` | `C = 12 + 18h` |
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`C = 12 + 6h`
`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 rule is:)\ \ C = 12 + 6h`
The value of `y` can be calculated by using the rule `y = 8 - x^2`.
What is the value of `y` when `x = 2.5?`
`1.75` | `3` | `5.5` | `6.25` |
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`1.75`
`y` | `= 8 – x^2` |
`= 8 – (2.5)^2` | |
`= 8 – 6.25` | |
`= 1.75` |
`y = 4x^2 - 7`
What is the value of `y` when `x = 3.1?`
`5.4` | `17.8` | `31.44` | `146.76` |
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`31.44`
`y` | `= 4 (3.1)^2 – 7` |
`= 38.44 – 7` | |
`= 31.44` |