<u>6,9 - 1,5 </u>= <u> 5,4 </u>= <u> 54 </u>=<u> 9 </u>= 2 ¹/₄
2,4 2,4 24 4
<span>3(4х-у)+4(2х+3у)-5(6х-2у)
12x-3y+8x+12y-30x+10y
-10x+19y x=2 y=-1
-10*2=-20 19*(-1)=-19
-20-19=-39</span>
<span>
(b²+2b+1)/(b²+8b+7)
</span><span>b²+2b+1=(b+1)²
</span>b²+8b+7= <span>b²+7b+b+7=b(b+7)+(b+7)=(b+7)(b+1)</span>
(b²+2b+1)/(b²+8b+7) = <span>(b+1)²/</span><span>(b+7)(b+1) = </span>(b+1)/<span>(b+7)</span>