Let's solve it step by step:
3( 10x − 14 ) = 9( 2x + 2 )
First, we can try to remove the multipliction outsude brackets to avoid complicating the steps.
(10x - 14x) = 9(2x + 2)/3
(10x - 14x) = 3(2x +2)
Then we can multiply 3 into the bracket on left hand side to remove the brackets.
10x - 14 = 3(2x) + 3(2)
10x -14 = 6x + 6
Put the unknown together:
10x - 6x = 6 + 14
4x = 20
x = 5
Therefore, the answer is D. x = 5.
Hope it helps!