Question

What is the reason for each proof?

Given: 3x - 4 = 2(x + 8), Prove: x = 20

(1) 3x - 4 = 2(x + 8)

(2) 3x - 4 = 2x + 16

(3) 3x = 2x + 20

Answer 1

Explanation:

We have given the expression:

3x - 4 = 2(x + 8)

Now multiply the R.H.S

3x-4 = 2x+16 (Distributive property)

Add 4 to both sides:

3x-4+4=2x+16+4

3x = 2x+20 (Addition property of equality)

Subtract 2x from both sides:

3x-2x = 2x-2x+20

x=20 (Subtraction property of equality)....