Question

sabendo que (2a+b, 3a +5b) = (-3,20) , o valor de 2a-b é:

Answer 1

Resposta:

2a+b=-3

3a+5b=20

6a+3b=-9

6a+10b=40

3b-10b=-9-40

-7b=-49

b=49/7

b=7

2a+7=-3

2a=-3-7

2a=-10

a=-10/2

a=-5

Portanto 2a-b=2*(-5)-7=-10-7=-17