643° Вправа 643Алгебра 8 клас Тарасенкова 2025 · § 15 · стор. 192

643. Спростіть вираз:

1) ${\displaystyle \frac{3}{\sqrt{c}}-\frac{4}{\sqrt{c}}=}$${\displaystyle \frac{3-4}{\sqrt{c}}=}$${\displaystyle -\frac{1}{\sqrt{c}}}$;

2) ${\displaystyle \frac{5}{\sqrt{p}}-\frac{2}{\sqrt{p}}=}$${\displaystyle \frac{5-2}{\sqrt{p}}=}$${\displaystyle \frac{3}{\sqrt{p}}}$;

3) ${\displaystyle \frac{2}{\sqrt{x}+8}-\frac{1}{8+\sqrt{x}}=}$${\displaystyle \frac{2-1}{\sqrt{x}+8}=}$${\displaystyle \frac{1}{\sqrt{x}+8}}$;

4) ${\displaystyle \frac{1}{\sqrt{x}-1}-\frac{\sqrt{x}}{\sqrt{x}-1}=}$${\displaystyle \frac{1-\sqrt{x}}{\sqrt{x}-1}=}$${\displaystyle \frac{-\cancel{\left(\sqrt{x}-1\right)}}{\cancel{\left(\sqrt{x}-1\right)}}=}$${\displaystyle -1}$.