Question

Given the point (5, 6) and the slope of 5, find y when x = 21.

Answer 1

y = 86

Explanation:

We know the slope is 5 so we can write our equation like this:

y = 5x + b

Since we know that (5, 6) is on our equation, we can substitute it into our equation:

6 = 5(5) + b

b = 6-25 = -19

Now we know our equation is y = 5x - 19

Next, we plug in 21 for x to find our y-value:

y = 5(21)-19 = 105-19 = 86