Answer:
[tex]y=8x-25[/tex]
Step-by-step explanation:
The first thing to do is to find the slope. The slope is the difference in Y divided by the difference in x, or:
[tex]m=\frac{y_2-y_1}{x_2-x_1}[/tex]
Here (3, -1) is going to be (x1, y1) and (4, 7) will be (x2, y2):
[tex]m=\frac{7--1}{4-3}=\frac{8}{1}=8[/tex]
The slope is 8. Now, you can plug that into the formula. To find the y-intercept, plug in any point on the line and solve for b:
[tex]y=mx+b\\-1=8(3)+b\\-1=24+b\\b=-25[/tex]
Now we have both the slope and the y-intercept so you can write the equation for the line:
[tex]y=8x-25[/tex]
You can test that either by checking y for some value of x, or by graphing.
