Question

considerando o sistema {3a-2b=20 ...?? {a+5b=1 o valor de 2a+3b e igual a ?

Answer 1

3a-2b=20
a+5b=1  ---> a=1-5b

3a-2b=20
3(1-5b)-2b=20
3-15b-2b=20
-15b-2b=20-3
-17b=17
b=17/-17
b=-1

a+5b=1
a+5(-1)=1
a-5=1
a=1+5
a=6

2a+3b=?
2(6)+3(-1)=?
12-3=9

2a+3b=9