Решение:<span><span>(<span>2,7x−3,2y</span>)</span><span>(<span>2,7x+3,2y</span>)</span>=</span>Раскрытие скобок:<span>7,29<span>x2</span>+8<span>1625</span>xy−8<span>1625</span>yx−10<span>625</span><span>y2</span>=</span><span>7,29<span>x2</span>−10<span>625</span><span>y2</span></span>Ответ: <span>7,29<span>x2</span>−10<span>625</span><span>y<span>2</span></span></span>
1)6а-3аb
б)60аb-25a²-36b²
в)2x³-2xy²-x²y+y³
<span>х²-10х+9 =
D = 100-36 = 64 (8)
x1 = (10+8):2 = 9
х2 = (10-8):2 = 1
</span><span>х²-10х+9 = (х-9)*(х-1)</span>
1) x/4+x/3=7/1
3x/12+4x/12+84/12
3x+4x=84
7x=84
x=84/7
x=12
2)2x/5+x/2=9/1
4x/10+5x/10=90/10
4x+5x=90
9x=90
x=90/9
x=10