Question

Given the point (3, 4) and the slope of 6, find y when x = 27.

Answer 1

The equation of a line is according to a formula, y = mx+b where m is the slope and b is the y intercept

You can find the full equation of the line using a point on it if you also know the slope, because you can plug in the point into the equation (for the x and y spots) to find the y intercept

So, plugging in all the info you have - 

4 = 6(3) + b

You then just have to solve for b.

4 = 18 + b

subtract 18 from both sides

-14 = b

b, the y-intercept, is -14. So the full equation of the line is y = 6x-14.

Then, to find y when x=27, you just plug in 27 for x and solve again.

y = 6(27) - 14
 
y = 148