-10 (3-4x)+51=7(5x+3)
25x²-10x+1-4=0
(5x-1)²-4=0
(5x-1)²-2²=0
(5x-1-2)(5x-1+2)=0
(5x-3)(5x+1)=0
x1=3/5, x2= -1/5 или x1=0,6, x2= -0,2