(6x³+3x²y):х²+(-10xy+15y²):(5у)=6х+3у-2х+3у=4х+6у=4*2+6*(-5)=-22.
2x*(x-21)²-x²*(x-21)=0
x*(x-21)*(2*(x-21)-x)=0
x*(x-21)*(2x-42-x)=0
x*(x-21)*(x-42)=0
x₁=0 x₂=21 x₃=42.
(22,5k³u³-1,5k²u⁴+7,5ku⁵)/(2,5ku³)=9k²-0,6ku+3u².
1) bx=a-4; x=(a-4)÷b
2)1÷a=1-bx;(1÷a-1)=-bx;x=1÷1-1÷b
3)ax-26=a-7(3+5/7x);ax-26=a-21-5x;-a-5=-5x-ax;-a-5=-x(5+a);(-a-5)/(5+a)=-x;-(5+a)÷(5+a)=-x;x=1
<span>x-4+x-6=2
2х= 2+4+8
2х= 12
х= 6</span>
31
1)7,52*5/9+11,48*5/9=5/9*(7,52+11,48)=5/9*19=95/9
2)95/9*100/38=(5*50)/(9*1)=250/9=27 7/9
33
1)20 4/5-4/5=20
2)1 5/12-3 1/3=1 5/12-3 4/12=1 5/12-2 16/12=-1 11/12
3)20-1 11/12=18 1/12
4)18 1/12:1 1/6=217/12*6/7=31/2
5)4*11/12+5*11/12=11/12(4+5)=11/12*9=33/4
6)31/2+31/4=62/4+33/4=95/4=23 3/4