1)(14a²-17ab-8b²)-(17ab+12a²-4b²)=14a²-17ab-8b²-17ab-12a²+4b²=
=2a²-34ab-4b²;
2)4a(a+2b)-7b(2a-b)-3a(2a-3b)=4a²+8ab-7ab+7b²-6a²+9ab=
=-2a²+10ab+7b²;
2)x(2x-2y)+x(2y-x)-2(x-y²)=2x²-2xy+2xy-x²-2x+2y²=x²-2x+2y²;
x=-0.1;y=0.7
(-0.1)²-2·(-0.1)+2·(0.7)²=0.01+0.2+0.98=1.19.
5v(2v²-v+3)-4v(v²-2v+5)-6v(v²+1/2·v-4)=10v³-5v²+15v-4v³+8v²-20v-6v³-3v²+24v=
=0·v³+0·v²+19v=19v;v=-7/19;⇒19v=19·(-7/19)=-7.
3)(3x-4)/3+(x-5)/4=2⇒[4·(3x-4)+3·(x-5)]/12=2 ⇒12x-16+3x-15=2·12=24;⇒
15x=16+15+24=55;⇒x=55/15=11/3;
7(1+6x)-4(3x-2)-9(9x+4)=30;⇒
7+ 42x-12x+8 - 81x - 36=30⇒ 42x-12x -81x=30-7-8+36 ⇒
-51x=51;
x=-1.