Question

Completely lost..... please help?

Answer 1

Question 1:

Straight line equation is given in the form $y=mx+c$, where:

m = the slope
c = the y-intercept

for this question, we have:
the slope, m = 5
y-intercept = -7

All you have to do is 'plug' these values into the equation

$y = 5x-7$
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Question 2:

We have:

the slope, m = 10
y-intercept, c = -3

Again, plug these values into the equation, we have:

$y = 10x-3$
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Question 3:

Here, we've got two coordinates instead. We don't have the slope, m, but we can work it out from the two coordinates

let (-1, 0) be (x₁, y₁) and (0,1) be (x₂, y₂)
Slope, m = $\frac{-1-0}{0-1} = \frac{-1}{-1}=1$

From the graph, we can read the y-intercept, c = 1

Now we have m =1 and c = 1, the equation is
$y=x+1$

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Question 4

We have two coordinates (-1, 0) and (0, 5)
Slope, m = $\frac{-1-0}{0-5} = \frac{-1}{-5}= \frac{1}{5}$
y-intercept, c = 5

Equation: $y = \frac{1}{5}x+5$