750 Вправа 750Алгебра 8 клас Бевз 2025 · § 15 · стор. 145

750. Знайди значення виразу: а) √(c²), якщо c = 3, c = −6, c = −12; б) x√(x²), якщо x = 5, x = −5, x = −7.

а) ${\displaystyle \sqrt{c^2}=}$${\displaystyle \left|c\right|}$;

${\displaystyle c=}$${\displaystyle 3}$ — ${\displaystyle \left|3\right|=}$${\displaystyle 3}$;

${\displaystyle c=}$${\displaystyle -6}$ — ${\displaystyle |-6|=}$${\displaystyle 6}$;

${\displaystyle c=}$${\displaystyle -12}$ — ${\displaystyle |-12|=}$${\displaystyle 12}$;

б) ${\displaystyle x\sqrt{x^2}=}$${\displaystyle x\left|x\right|}$;

${\displaystyle x=}$${\displaystyle 5}$ — ${\displaystyle 5\cdot \left|5\right|=}$${\displaystyle 5\cdot 5=}$${\displaystyle 25}$;

${\displaystyle x=}$${\displaystyle -5}$ — ${\displaystyle -5\cdot |-5|=}$${\displaystyle -5\cdot 5=}$${\displaystyle -25}$;

${\displaystyle x=}$${\displaystyle -7}$ — ${\displaystyle -7\cdot |-7|=}$${\displaystyle -7\cdot 7=}$${\displaystyle -49}$.