Question

Mim ajudem e pra mim ver se acertei a prova

Answer 1

2x + y = 7

y = 7 - 2x

2x - 3y = 3

2x - 3 × (7-2x) = 3

2x - 21 + 6x = 3

8x = 3 + 21

8x = 24

$x = \frac{24}{8}$

x= 3

y = 7 - 2x

y = 7 - 2 × (3)

y = 7 - 6

y = 1

12x + 3y = 15 : (3)

4x + y = 5

y = 5 - 4x

2x - 3y = 13

2x - 3 × (5-4x) = 13

2x - 15 + 12x = 13

14x = 13 + 15

14x = 28

$x = \frac{28}{14}$

x= 2

y = 5 - 4x

y = 5 - 4 × (2)

y = 5 - 8

y = - 3