Question

Os sistemas x+y =20
x-y=4 e ax

Answer 1

x+y=20
x-y=4

x=20-y
20-y-y=4
-2y=4-20
-2y=-16
y=16/2
y=8

x=20-y
x=20-8
x=16

ax+2y=32
3x-by=20, se x=16 e y=8, então:

a.16+2.8=32
3.16-b.8=20

16a+16=32
16a=32-16
16a=16
a=16/16
a=1

48-8b=20
-8b=20-48
-8b=-28
b=28/8
b≈3,5