1)x^2+9x+8 (x+1)(x+8) (x+8)
==
3x^2+8x+5 3(x+1)(x+1 2/3) 3x+5
x^2+9x+8=0 3x^2+8x+5=0
D= 8^2-4*3*5=64-60=4
x1+x2=-9| -8(+)-))2
x1,2=
|-8;-1 6
x1x2=8 | x1=-1 ; x2=-1 2/3
2)
a)x(x+3)-4(x-5)=7(x+4)-8
x^2+3x-4x+20=7x+28-8
x^2-8x=0
x(x-8)=0
x=0 или х-8=0
х=8
б)2x^4-9x+4=0
D=(-9)^2-4*2*4=81-32=49
9(+(-))7
x1,2=
4
x1=4; x2=0.5
1.
а)2(х2-2х+3)-3(2х2+х-1)
2*3-3(4х+х-1)
6-3(5х-1)
6-15х+3
9-15х
b)-4b(b2-2b)-2b(3b-b2)
-4b*0-2b(3b-2b)
0-2b*b
-2b^2
c)4(2x-3y)-(2x+5y)+3(y-2x)
4(2x-3y)-(2x+5y)+3(y-2x)
8x-12y-2x-5y+3y-6x
0-14y
-14y
2.
a)2(1-3x)=14
1-3x=7
-3x=7-1
-3x=6
x=-2
b)8-3(y-2)=4
8-3y+6=4
14-3y=4
-3y=4-14
-3y=-10
y=10/3
c)2(x-3)+4(x+3)=0
2x-6+4x+12=0
6x+6=0
6x=-6
x=-1
d)y(2-3y)+3y(1+y)=15
y(2-3y)+3y(1+y)=15
2y-3y^2+3y+3y^2=15
5y=15
y=3
e)2(x-1)-3=5(2x-1)-7x
2x-2-3=10x-5-7x
2x-5=3x-5
2x=3x
2x-3x=0
-x=0
x=0
f)2x(6x-2)=7x(2x-4)-2x2
12x^2-4x=14x^2-28x-4x
12x^2=14x^2-28x
12x^2-14x^2+28x=0
-2x^2+28x=0
-2x(x-14)=0
x(x-14)=0
x=0 x-14=0
x=0 x=14
