1) 9+2(2х+1)=1
9+4х+2=1
4х= -10
х= -2,5
2) 4+3(10х+7)= -5
4+30+21= -5
30х= -30
х= -1
3) 4+5(-3х+7)= -9
4-15х+35= -9
-15х=-48
х=3,2
![\left \{ {{-5x+3 \leq 0} \atop {x+1 \geq -2}} \right. \\\\ \left \{ {{x \leq 0.6} \atop {x \geq -3}} \right. \\\\b_1=1\\b_2=5b_1=5\\b_3=5b_2=5*5=25\\b_4=5b_3=25*5=125\\\\](https://tex.z-dn.net/?f=%5Cleft+%5C%7B+%7B%7B-5x%2B3+%5Cleq+0%7D+%5Catop+%7Bx%2B1+%5Cgeq+-2%7D%7D+%5Cright.+%5C%5C%5C%5C+%5Cleft+%5C%7B+%7B%7Bx++%5Cleq++0.6%7D+%5Catop+%7Bx+%5Cgeq+-3%7D%7D+%5Cright.+%5C%5C%5C%5Cb_1%3D1%5C%5Cb_2%3D5b_1%3D5%5C%5Cb_3%3D5b_2%3D5%2A5%3D25%5C%5Cb_4%3D5b_3%3D25%2A5%3D125%5C%5C%5C%5C)
Только 125 подходит
Начало координат (0,0), через нее проходит только y=-5x²+x
Cos(2x+π/4-x)=√2/2
cos(x+π/4)=√2/2
x+π/4=-π/4+2πn U x+π/4=π/4+2πn
x=-π/2+2πn U x=2πn