Question

Solve by substitution y = 2x - 5 and 3y - x = 5

Answer 1

(x, y) = (4, 3)

Explanation:

The first equation gives an expression for y that can be substituted into the second equation:

3(2x -5) -x = 5

5x -15 = 5 . . . . . . simplify

5x = 20 . . . . . . . .add 15

x = 4 . . . . . . . . . . divide by 5

y = 2(4) -5 = 3 . . substitute for x in the first equation

(x, y) = (4, 3)

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Solution by graphing confirms this result.