Question

Determine o valor de a e b

a + 2a - b =30

a + a + b =20

Answer 1

b= 20-2a
______
a+2a-(20-2a)=30
a+2a-20+2a=30
5a=30+20
5a=50
a=50÷5
a=10
_______
b=20-2a
b=20-2(10)
b=20-29
b=0