Question

alguém me ajuda por favorr preciso pra amanhã ​

Answer 1

1) y=6

3x-7y=-12

3x-7(6)=-12

3x-42=-12

3x=-12+42

3x=30

x=10.

S={10,6}

2) y=4-2x

5x-2y=1

5x-2(4-2x)=1

5x-8+4x=1

9x=9

x=1.

y=4-2

y=2

S={1,2}

3) $x=\frac{y+3}{2}$

7x-3y=6

$\frac{7(y+3)}{2}-3y=6\\\\\frac{7y+21}{2}-3y=6\\\\\frac{y+21}{2}=6\\\\12=y+21\\12-21=y\\ y=-9$

x=(-9)+3/2

x=-3

S= {-3,-9}