Question

Justify each step of the proof.
Conjecture: If 2(x^2+5) = 60, then x is 5 or -5

Answer 1

X is 5 and negative 5.
2(x^2+5)=60
Divide both sides by 2
X^2+5=30
Subtract 5 on both sides
X^2=25
The square route of 25 is 5 or -5.