1)(4x-3)*(4x+3)-(4x-1)²=3x
(16x²-9)-(16x²-8x+1)=3x
16x²-9-16x²+8x-1=3x
8x-10=3x
8x-3x=10
5x=10
x=10:5
x=2
2)3*(x-1)²-3x*(x-5)=21
3*(x²-2x+1)-3x²+15x=21
3x^2-6x+3-3x²+15x=21
-6x+15x=21-3
9x=18
x=18:9
x=2
3)10*(x-2)²-5x(2x-1)=-4
10*(x²-4x+4)-10x²+5x=-4
10x²-40x+40-10x²+5x=-4
-35x=-4-40
-35x=-44
x=-44:(-35)
x=1 9/35
4)(5x+6)²-(5x-6)²=12
(25x²+60x+36)-(25x²-60x+36)=12
25x²+60x+36-25x²+60x-36=12
120x=12
x=12:120
x=0,1
5)(3-2x)²-(2x-2)²=4
(9-12x+4x²)-(4x²-8x+4)=4
9-12x+4x²-4x²+8x-4=4
-4x=-1
x=0,25
6)(5-3x)²-17x=3x(3x-2)+12
(25-30x+9x²)-17x=9x²-6x+12
25-30x+9x²-17x=9x²-6x+12
-30x+9x²-17x-9x²+6x=12-25
-47x=-13
x=-13:(-45)
x=13/45