1) (x+5)*(x+5)=(x-5)*(x-5)
x^2+10x+25=x^2-10x+25
x^2+10x-x^2+10x=25-25
20x=0
x=0
2) (4x+1)*x=(3x-1)*3
4x^2+x=9x-3
4x^2+x-9x+3=0
4x^2-8x+3=0
D= (-8)^2-4*4*3=64-48=16
x1= (8-4)/2*4=4/8=1/2=0,5
x2=(8+4)/2*4=12/8=3/2= 1,5
3) (x-4)*x=(10+2x)*2
x^2-4x=20+4x
x^2-4x-20-4x=0
x^2-8x-20=0
x1+x2=8 x1= 10
x1*x2= -20 x2= -2
4) (4x+1)*(x+1)= (3x-8)(x-3)
4x^2+4x+x+1=3x^2-9x-8x+24
4x^2+4x+x+1-3x^2+9x+8x-24=0
x^2+22x-23=0
x1+x2= -22 x1= -23
x1*x2= -23 x2= 1