2. justify each step of the proof.
conjecture: if 2(x2 + 5) = 60, then x is 5 or –5.
1. 2(x2 + 5) = 60 1.
2. 2x2 + 10 = 60 2.
3. 2x2 = 50 3.
4. x2 = 25 4.
5. x = ±5 5.

Hello,

2(x²+5)=60
<==>x²+5=30 (divided teh 2 members by the positive 5 :keep the equality)
<==>x²-25=0 (substract 25 from 2 members)
<==>(x-5)(x+5)=0 (remarquable product a²-b²=(a+b)(a-b))
<==> x= 5 or x=-5 (a product if null if one at least of its factor is null)

Atranslation 6 units to the right and 4 down