X+y=8
y=8-x
3x+8-x=12
2x=12-8
2x=4
x=4:2
x=2
3*2+(8-2)=12
6+6=12
<span>1)x^2-100x=0
х(х-100)=0
х=0
х-100=0
х=100
2)9/25(дробь)x^3-x=0
х(9/25х</span>²-1)=0
<span>х=0
(3/5х-1)(</span>3/5х+1)=0
3/5х=1
х=5/3
3/5х+1=0
х=-5/3
<span>3)25y^2+20y+4=0
(5у+2)</span>²=0
<span>5у+2=0
5у=-2
у=-2/5
4)36x^2+25=60x
36х</span>²-60х+25=0
<span>(6х-5)</span>²=0
<span>6х-5=0
6х=5
х=5/6
5)x^4-x^2=0
х</span>²(х²-1)=0
<span>х</span>²=0
<span>х=0
(х-1)(х+1)=0
х=1
х=-1
6)x^5-49x^3=0
х</span>³(х²-7)=0
<span>х</span>³=0
<span>х=0
х</span>²-7=0
<span>х</span>²=7
<span>х=</span>√7
<span>х=-</span>√7<span>
7)x^3+2x^2-9x-18=0
х</span>²(х+2)-9(х+2)=0
<span>(х+2)(х</span>²-9)=0
<span>х+2=0
х=-2
(х-3)(х+3)=0
х=3
х=-3
8)y^3-3y^2-4y+12=0
у</span>²(у-3)-4(у-3)=0
(у²-4)(у-3)=0
(у-2)(у+2)(у-3)=0
у=2
у=-2
у=3
2р(3р+4)-2р(2р-3)=6р²+8р-4р²+6р=2р²+14р