Graphs 2
2 marks · EasyHere is a table showing a relationship between $x$ and $y$.
| $x$ | $y$ |
|---|---|
| 0 | 3 |
| 1 | 5 |
| 2 | 7 |
Describe the relationship between $x$ and $y$.
Work out the next value of $y$ when $x = 3$.
Work this out on paper, then compare with the answer and worked solution below. With a free account you can submit written answers for marking.
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(a) $y$ increases by $2$ each time $x$ increases by $1$; $y$ is $2x + 3$
(b) 9
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Marking points
B1 (a) · 1 mark · States $y$ increases by 2 for each increase of 1 in $x$, or $y = 2x + 3$.
A1 (b) · 1 mark · Finds $y = 9$ when $x = 3$.
Worked solution
a) For $x$ from $0$ to $1$, $y$ increases from $3$ to $5$ (by $2$). From $1$ to $2$, $y$ increases from $5$ to $7$ (again by $2$).
So the relationship is $y = 2x + 3$.
b) When $x = 3$, $y = 2 \times 3 + 3 = 6 + 3 = 9$.