Question

-1 e a raiz das equaçoes abaixo:
a) 3×-40=×-42
b) 15-3×=×+20
c) 12×-10×+9=×-2×

Answer 1

a)
3x-40=x-42
3x-x=-42+40
2x=-2
x=-2/2
x=1

b)
15-3x=x+20
-3x-x=20-15
-4x=5
x=-4/5

c)
12x-10x+9=x-2x
12x-10x-x+2x=-9
14x-11x=-9
3x=-9
x=-9/3
x=-3

resp A