Answer:
The y-intercept is -58
The equation is y=7x-58
Explanation:
We'll look for an equation of the form y=mx+b, where m is the slope and b the y-intercept (the value of y when x is 0).
We are given the slope and one point on a line. The slope, m, of 7 leads us to:
y=7x+b
We need a value for b that will force the line to go through point (4,-30). Enter that point in the above equation and solve for b:
y = 7x+b
-30 = 7(4)+b for point (4,-30)
-30 = 28 + b
b = -58 [b is the y-intercept]
The equation is y = 7x-58
See the attached graph.