1)х(4-у)
2)а^4(a^3+1)
3)12x^2(2^y+3y)
4)-4a(2b+3*2b+6^b)
5)x^2(x^2+6x+9x)
6cos60°-4sin30°+6ctg60°-8ctg30°=
=6.1/2 -4.1/2+6.√3/3 -8.√3=6/2-4/2+2√3-8√3=
=3-2-2√3=1-2√3
(cos60°=sin30°=1/2,ctg60°=tg30°=(√3)/3, ctg30°=tg60°=√3)
3,7,11,15,19,23,27,31,35 и т . д .
<span>(х-3у=4 x=4+3y</span>
<span>(2х+у=15 2*(4+3y)+y=15 8+6y+y=15 7y=7 y=1</span>