Question

How do you solve `y = 3x + 5` and `y = 2x + 4`?

Answer 1

The answer is y=2 and x=-1.

Explanation:

In order to eliminate one of the variables, say x, transform the equation (2) `y=2x+4`, by multiplying both sides by 3/2. The result is (2') `3/2 y = 3x + 6`. Now, subtract equation (1), namely `y = 3x + 5`, from equation (2'), and one gets `1/2 y = 1`.So, y = 2. Substituting 2 for y in equation (1) one gets `2=3x+5`, and by subtracting 5 from both sides, one gets `-3=3x`. So, x = -1.