12а²+8аb 4а(3а+2b) 4a
----------------------- = --------------------= ------------------------
3ab+2b² b(3a+2b) b
. a=0,5 b=0,2
4*0,5
---------- = 10
0.2
x²-6xy+9y² (х-3у)² х-3у
------------------ = ------------------ = -------------------------
2x²-6xy 2х(х-3у) 2х
x=1,5
y=-0,5
1,5 - 3*(-0,5) 1,5 +1,5
---------------------- = -------------- = -3
2*(-0,5) -1
===================
0,2 * 2,6 + 6,89=<span>7.41</span><span>
1)</span><span>0,2 * 2,6 =0.52
2)0.52+6.89=7.41
==================</span>
1/2+1/5=5/10+2/10=7/10 или 0,7
1/2+1/8=4/8+1/8=5/8
1/2+1/3=3/6+2/6=5/6
1/2+1/6=3/6+1/6=4/6=2/3
1/2+1/4=2/4+1/4=3/4
1) 1,2а-(0,2а+b)=1,2a-0,2a-b=a-b
2) 0,7x-(2y-0,7x)=0,7x-2y+0,7x=1,4x-2y
3) 0,1(x-2y)+0,2(x+y)=0,1x-0,2y+0,2x+0,2y=0,3x
4) 2/3(m-3n)+1/3(n-2m)=2/3m-2n+1/3n-2/3m=-1 2/3n
5) 8(a+3b)-9(a+b)=8a+24b-9a-9b=15b-a
6) 3(c+d)-7(d+2c)=3c+3d-7d-14c=-4d-11c
<span>3(5-3x)=6(x+5)
15-9x=6x+30
-9x-6x=30-15
-15x=15
x=-1
3(2y-1)=9
6y-3=9
6y=9+3
6y=12
y=12:6
y=2</span>