Question

A)2x-3y=21parax=3
B)6x+4y=12paray=2
C)-10x-2y=30parax=2
D)5x-3x+y-y=22parax=4

Answer 1

Olá!

a) x = 3
$2x - 3y = 21 \\ 2 * 3 - 3y = 21 \\ 6 - 3y = 21 \\ - 3y = 21 - 6 \\ - 3y = 15(-1) \\ 3y = - 15 \\ y = \frac{15}{3} \\ y = - 5$
S = {-5}

b) y = 2
$6x + 4y = 12 \\ 6x + 4 * 2 = 12 \\ 6x + 8 = 12 \\ 6x = 12 - 8 \\ 6x = 4 \\ x = \frac{4}{6} \\ x = \frac{2}{3}$
S = {2/3}

c) x = 2
$- 10x - 2y = 30 \\ - 10 * 2 - 2y = 30 \\ - 20 - 2y = 30 \\ - 2y = 30 + 20 \\ - 2y = 50 (-1) \\ 2y = - 50 \\ y = \frac{- 50}{2} \\ y = - 25$
S = {-25}

d) x = 4
$5x - 3x + y - y = 22 \\ 5x - 3x = 22 \\ 2x = 22 \\ x = \frac{22}{2} \\ x = 11$
S = {11}