1. 3x^2-(5+2x^2)-(x^2-7x)=0
3x^2-5-2x^2-(x^2-7x)=0
x^2-5-(x^2-7x)=0
0-5+7x=0
-5+7x=0
7x=5
x=5/7
2.4x^2-(6+x^2)-(3x^2-11x)=0
4x^2-6-x^2-(3x^2-11x)=0
3x^2-6-(3x^2-11x)=0
3x^2-6-3x^2+11x=0
0-6+11x=0
-6+11x=0
11x=6
x=6/11
3.3x^2-(6x+2x^2)-(x^2+7)=0
3x^2-6x-2x^2-(x^2+7)=0
x^2-6x-(x^2+7)=0
x^2-6x-x^2-7=0
0-6x-7=0
-6x=7
x=-7/6
4.4x^2-(7x-x^2)-(3x^2-8)=0
4x^2-7x-x^2-(3x^2-8)=0
3x^2-7x-(3x^2-8)=0
3x^2-7x-3x^2+8=0
0-7x+8=0
-7x=-8
x=8/7