1) 4a-12b=4(a-3b)
2)9-5x=2(4,5-2,5x)
3)3x-2a=2(1,5-a)
4)25b-15=5(5b+3)
5) ax(b-c)+c(b-c)=axb-axc+cb-c2
7) (x+y)+m(-x-y)=x+y-mx-my
2)-(2-y)=-2+y
1,2)3x(-2ax+(-1))=3x(-2ax-1)=-6ax2-3x
<span>i6+i20+i30+i36+i54 правильно списал(а) ?</span>
0.6x+1.2-1.2x+1.8=4x-20
-0.6x+3=4x-20
-4.6x=-23
x=0.2
2x^2-x=2x-1
2x^2-3x+1=0
D=9-8=1
x1=(3+1)/4=1, y1=1
x2=(3-1)/4=1/2, y2=0
1) (2c+3)^2-(3-c)*(c+3)=4c^2+12c+9-(9-c^2)=4c^2+12c+9-9+c^2=4c^2+12c+c^2=5c^2+12c
2) (x^12:x^6)^2/x^4*x^3=x^12/x^4*x^3=x^8*x^3=x^11