Вправи: 351

351. Знайдіть х, якщо:

1) a^–1b²⁴ = a⁵b^–8 • x;

x = a-1b24a5b-8 = a^–6b³².

2) a^–1b^–1 = x : ab;

x = a^–1b^–1 • ab = a⁰b⁰ = 1 • 1 = 1;

3) a^–7b²⁶ = x : b^–16;

x = a^–7b²⁶ • b^–16 = a^–7 • b¹⁰;

4) 1,9²¹ = (1,9^–3)^–x;

1,9²¹ = 1,9^3x;

3x = 21|: 3;

x = 7.

5) (4,5)^–20 = (4,5^–x)⁵;

(4,5)^–20 = (4,5)^–5x;

–5x = –20|: (–5) ;

x = 4.