a). 2(3x+4)-3(5x-6)+4(7x+8)=115 b).x(x-5)-x(x+4)=-63 c).6x-7(11+2x)+2=-4(15-x)+3x d).3(5x+3)=7(x+5)-3(2-x)

a) 2(3x+4)-3(5x-6)+4(7x+8)=115 6x+8-15x+18+28x+32=115 6x-15x+28x=115-8-18-32 19x=57 | /19 x=3 b) x(x-5)-x(x+4)=-63 x²-5x-x²-4x=-63 x²-x²-5x-4x=-63 -9x=-63 | / (-9) x=7 c) 6x-7(11+2x)+2=-4(15-x)+3x 6x-77-14x+2=-60+4x+3x 6x-14x-4x-3x=-60+77-2 -15x=15 | /(-15) x=(-1) d) 3(5x+3)=7(x+5)-3(2-x) 15x+9=7x+35-6+3x 15x-7x-3x=35-6-9 5x=20 | /5 x=4

a). 2(3x+4)-3(5x-6)+4(7x+8)=115 6x+8-15x+18+28x+32=115 6x-15x+28x=115-32-18-8 19x=57 /:19 x=3 b).x(x-5)-x(x+4)=-63 x²-5x-x²-4x=-63 -9x=-63 /:(-9) x=7 c).6x-7(11+2x)+2=-4(15-x)+3x 6x-77-14x+2=-60+4x+3x 6x-14x-4x-3x=-60-2+77 -15x=15 /:(-15) x=(-1) d).3(5x+3)=7(x+5)-3(2-x) 15x+9=7x+35-6+3x 15x-7x-3x=35-6-9 5x=20 /:5 x=4

a). 2(3x+4)-3(5x-6)+4(7x+8)=115 6x+8-15x+18+28x+32=115 19x+58=115 19x=57 x=3 b).x(x-5)-x(x+4)=-63 x(kwadrat)-5x-x(kwadrat)-4x=-63 -9x=-63 x=7 c).6x-7(11+2x)+2=-4(15-x)+3x 6x-77-14x+2=-60+4x+3x -8x-75=-60+7x -x=-15 x=15 d).3(5x+3)=7(x+5)-3(2-x) 15x+9=7x+35-6+3x 15x+9=10x+29 5x=20 x=4