Question

x + 3y = 7 ; 2x + 3y = 8

A) x=1 , y=2
B) x=-2 , y=3
C) x=-1 , y=-2
D) x=0 , y=0

Answer 1

Respuesta:

x=1

y=2

Explicación paso a paso:

$x + 3y = 7 \: \: \: ( \times - 2) \\ - 2x - 6y = - 14 \\ 2x + 3y = 8 \\ - 3y = - 6 \\ 3y = 6 \\ y = \frac{6}{3} = 2 \\ \\ x + 3y = 7 \\ x = 7 - 3y \\ x = 7 - 3 \times 2 \\ x = 7 - 6 = 1 \\ x = 1$

$a)1 + 2 \times 3 = 1 + 6 = 7 \\ b)2 \times 1 + 3 \times 2 = 2 + 6 = 8$

espero te sirva