Question

A)se A+10=B+10,entao A=? B)Se A=B,entao A+5=B+? c)Se x=3 e y=2 ,entao x+y=3+?

Answer 1

A + 10 = B + 10
A - B = 10 - 10
A - B = 0
A = B

A + 5 = B + x
A - B = x - 5
A = B
x - 5 = 0
x = 0

x + y = 3 + z
3 + 2 = 3 + z
5 = 3 + z
5 - 3 = z
z = 2

Espero ter ajudado :P