Question

Algm poderia me ajudar nesse sistema? pfvr

a/3 = b/4
3a + 4b = 20

Answer 1

Resposta:

a=12/5 e b=16/5

Explicação passo-a-passo:

a/3=b/4 mmc=12

3a+4b=20

________

4a=3b

3a+4b=20

_________

4a-3b=0 ×(-3)

3a+4b=20 ×(4)

____________

-12a+9b=0

12a+16b=80

___________

0a+25b=80

25b=80

b=80/25 :(5/5)=

b=16/5 , vamos encontrar A

4a-3b=0

4a-3x16/5=0

4a-48/5=0 mmc=5

20a-48=0

20a=48

a=48/20 :(4/4)

a=12/5