А) 49-14а+а²-(5а+35+а²+7а)= 49-14а+а²-(12а+35+а²)= 49-14а+а²-12а-35-а²=14-26а
X²+3x-10/x+5
Запишем обычное деление столбиком:
x²+3x-10 / x+5
- _____
x²+5x / x-2
_______/
-2x-10/
- /
<span>-2x-10/
_______
0
Т.о. </span>x²+3x-10=(x+5)(x-2) => x²+3x-10/x+5=<span>(x+5)(x-2)/x+5=x-2</span>
A)(a5)3÷a8×a2=a15÷a8×a2=a9
= 24n - 6n² + 16 - n² = -7n² + 24n +16
<span>3*(5-2х)+7=3-4х</span>