(7x+1)(x-3)+20(x-1)(x+1) = 3(3x-2)²+13
7x²-20x-3+20x²-20 = 27x²-36x+12+13
27x²-20x-23=27x²-36x+25
36x-20x = 25+23
16x = 48
x = 3
(7x+1)(x-3)+20(x-1)(x+1) = 3(3x-2)²+13
7x²-20x-3+20x²-20 = 27x²-36x+12+13
27x²-20x-23=27x²-36x+25
36x-20x = 25+23
16x = 48
x = 3