a)16.(5x-1)^2 = 9.(3x+5)^2
4^2.(5x-1)^2 = 3^2.(3x+5)^2
[4.(5x-1)]^2 = [3.(3x+5)]^2
(20x-4)^2 = (9x+15)^2
=>(20x-4)^2 - (9x+15)^2 = 0
[(20x-4)+(9x+15)].[(20x-4)-(9x+15)] = 0
(29x+11).(11x-19) = 0
=> 29x+11=0 hoặc 11x-19=0
=> x=11/29 hoặc x= 19/11
b)(3x^2+10x-8)^2 = (5x^2 - 2x +10)^2
=> (5x^2 - 2x +10)^2 - (3x^2+10x-8)^2 = 0
[(5x^2 - 2x +10)+(3x^2+10x-8)].[(5x^2 - 2x +10) - (3x^2+10x-8)] = 0
(8x^2 - 8x + 2).(2x^2-12x+18)=0
2.(4x^2-4x+1).2.(x^2-6x+9)=0
4.(2x-1)^2.(x-3)^2=0
=> (2x-1)^2=0 hoặc (x-3)^2=0
=> 2x-1 = 0 hoặc x-3=0
=> x=1/2 hoặc x=3