1) 150:100*12=18(рублей) повысилась зарплата
2lg(x+3)=lg(ax)
x+3>0 U ax>0⇒x>-3 U ax>0
lg(x+3)²=lg(ax)
(x+3)²=ax
x²+3x-ax+9=0
x²+x(3-a)+9=0
D=(3-a)²-36=0
(3-a)²=36
3-a=-6 или 3-a=6
a=9 x∈(0;∞) или a=-3 x∈(-3;0)
<span>А) 2u-3(7-2u) = 3
2u-3*7-3*(-2u) = 3
2u-21+6u = 3
2u+6u = 3+21
8u = 24
u = 24:8
u = 3
Б) 12-y = 5(4-2y)+10
12-y = 5*4+5*(-2y)+10
12-y = 20-10y+10
-y+10y = 20+10-12
9y = 18
y = 18:9
y = 2
В) 2-2(x-8) = 4x-4
2-2*x-2*(-8) = 4x-4
2-2x+16 = 4x-4
-2x-4x = -4-2-16
-6x = -22
x = -22:(-6)
x = 3</span>⁴/₆
x = 3²/₃