x = 30
The distributive property says that we need to multiply what's in the brackets by 1/2 (so 1/2*x and 1/2*6) to get the equation 1/2x + 3 = 18.
Then we need to subtract our constant, 3, from boths sides to get 1/2x = 15.
Multiply both sides by two to isolate x and you get x = 30.
Hope this helps! :)
ANSWER

EXPLANATION
The point-slope equation of a straight line is given by:

Where m is the slope.
The line goes through (-5,4) and (1,6).
The slope of this line is,


The point-slope equation is
