Question

a line is written in standard form ax+by=c where a does not =0 find the x-coordinate of the point on the line at which y=3

Answer 1

x = (c -3b)/a

Explanation:

Substitute 3 for y and solve for x.

ax +b·3 = c

ax = c -3b . . . . . . . subtract 3b

x = (c -3b)/a . . . . . divide by the x-coefficient