Question

Substitution:
X + 2y = 13
-2x - 3y = -18

Answer 1

x = -3

y = 8

Explanation:

x + 2y = 13 ------------(I)

x = 13 - 2y -----------(II)

-2x - 3y = -18 ----------(III)

Substitute x = 13 - 2y in equation (III)

-2*(13 - 2y) - 3y = -18

-2*13 - 2y *(-2) -3y = -18

-26 + 4y - 3y = -18 {Combine like terms}

-26 + y = -18 {Add 26 to both sides}

y = -18 + 26

y = 8

Substitute y = 8 in equation (II)

x = 13 - 2*8

= 13 - 16

x = -3

x = -3

y = 8