X+5 >или равно 3
<span>X > или равно -2</span>
<span>1) 5х(12х -7) - 4х(15х - 11)= 30+29х
60x</span>²-35х-60х<span>²+44х=30+29х
44х-35х-29х=30
-20х=30
х=-1,5
</span><span>2) 2х(х-8)=(х+1)(2х-3)
</span> 2х²-16х=2х<span>²-3х+2х-3
2х</span>²-2х<span>²-16х+3х-2х=-3
-15х=-3
х=0,2
3) </span>2х(2-3х)(3х+2)-8х+18х³= 2х(6х+4-9х²-6х)-8х+18х³= 2х(4-9х²)-8х+18х³=8х-18х³-8х+18х<span>³=0
</span>
4) х<span>²=(х-1)(х-2)+16
</span> х²=х<span>²-2х-х+2+16
</span> х²-х<span>²+2х+х=2+16
</span><span> 3х=18
х=6
</span>
5-6cos^2a
1) cos^2a=1-(-3/8)^2
2) -6cos^2a=-330/64
3) 5-330/64= (320-330)/64=-5/32