1)(4x+6)(3x-2)=(6x-5)(2x+8)

12x²-8x+18x-12=12x²+48x-10x-40

12x²-8x+18x-12x²-48x+10x=-40+12

-28x=-28

x=1

2)(2x-3)(5x-1)=10x²-31

10x²-2x-15x+3=10x²-31

10x²-2x-15x-10x²=-31-3

-17x=-34

x=2

3)(7x-1)(x+5)=(3+7x)(x+3)

7x²+35-x-5=3x+9+7x²+21x

7x²-x-3x-7x²-21x=9-35+5

-25x=-21

x=21/25

4)(4x-1)(4x-3)=16x²-13

16x²-12-4x+3=16x²-13

16x²-4x-16x²=-13+12-3

-4x=-2

x=1/2

x=0,5