13(x-13)+12(x-12)=2(x-12)(x-13)
13x-169+12x-144=2(x²-13x-12x+156)
25x-313=2(x²-25x+156)
25x-313=2x²-50x+312
2x²-75x+625=0
D=75²-4*2*625=625
√D=25
x₁=(75-25)/4=12,5
x₂=(75+25)/4=25
8(x-8)+3(x-3)=2(x-8)(x-3)
8x-64+3x-9=2(x²-3x-8x+24)
11x-73=2(x²-11x+24)
11x-73=2x²-22x+48
2x²-33x+121=0
D=33²-4*2*121=121
√D=11
x₁=(33-11)/4=5,5
x₂=(33+11)/4=11