Question

pfvrrr!!!! eu preciso pra hj​

Answer 1

Explicação passo-a-passo:

a) 2.( 6y) - 7y= 10

12y-7y=10

5y=10

y=10/5

y=2

x=12(basta substituir na equação)

(12,2)

b) 4x -(7-x)=8

4x-7+x=8

5x=8+7

5x=15

x= 15/5

x=3

y=4(basta substituir na equação)

(3,4)

Answer 2

Resposta:

A)x=-12 y= -2

B)x=3 y=4

C)x=7 y=2

D)x= 2 y=-1

Explicação passo-a-passo:

$\\A)\left \{ {{x=6y} \atop {2x-7y}} \right. \\\\2*(6y) - 7y = -10\\12y-7y=-10\\5y=-10\\y=-2\\x=-12\\\\B)\left \{ {4x-y=8} \atop {x+y=7}} \right. \\y=7-x\\4x-(7-x)=8\\4x-7+x=8\\5x=15\\x=3\\y=4\\\\C)\left \{ {{x+y=9} \atop {x-y=5}} \right. \\x=5+y\\5+y +y =9\\2y=4\\y=2\\x=7\\\\D)\left \{ {{x-3y=5} \atop {2x+4y=0}} \right. \\x=5+3y\\2*(5 + 3y) +4y=0\\10 +6y+4y=0\\10y=-10\\y=-1\\x=2$