Đáp án: a ) n = 3 b ) n = 2 c ) n = 2 Giải thích các bước giải: a ) $\frac{-32}{-2^n}$ = 4 → $-2^{n}$ . 4 = -32 → $-2^{n}$ = -8 → $-2^{n}$ = $-2^{3}$ → n = 3 b ) $\frac{8}{2^n}$ = 2 → 8 = $2^{n}$ . 2 → $2^{3}$ = $2^{n+1}$ → 3 = n + 1 → n = 2 c ) $(\frac{1}{2})^{2n-1}$ = $\frac{1}{8}$ → $(\frac{1}{2})^{2n-1}$ = $(\frac{1}{2})^{3}$ → 2n – 1 = 3 → 2n = 4 → n = 2 Reply
`a,[-32]/[-2^n]=4` `⇔ [32]/[2^n]=4/1` `⇔ 2^n . 4 = 32.1` `⇔ 2^n = 32 ÷ 4` `⇔ 2^n = 8` `⇔ 2^n = 2^3` `⇔ n = 3` `b, 8/[2^n] = 2` `⇔ 8 = 2^n . 2` `⇔ 2^3 = 2^[n+1]` `⇔ 3 = n + 1` `⇔ n = 2` `c, (1/2)^{2n-1} = 1/8` `⇔ (1/2)^{2n-1} = (1/2)^3` `⇔ 2n – 1 = 3` `⇔ 2n = 4` `⇔ n = 2` Xin hay nhất ! Reply
Đáp án: a ) n = 3
b ) n = 2
c ) n = 2
Giải thích các bước giải:
a ) $\frac{-32}{-2^n}$ = 4
→ $-2^{n}$ . 4 = -32
→ $-2^{n}$ = -8
→ $-2^{n}$ = $-2^{3}$
→ n = 3
b ) $\frac{8}{2^n}$ = 2
→ 8 = $2^{n}$ . 2
→ $2^{3}$ = $2^{n+1}$
→ 3 = n + 1
→ n = 2
c ) $(\frac{1}{2})^{2n-1}$ = $\frac{1}{8}$
→ $(\frac{1}{2})^{2n-1}$ = $(\frac{1}{2})^{3}$
→ 2n – 1 = 3
→ 2n = 4
→ n = 2
`a,[-32]/[-2^n]=4`
`⇔ [32]/[2^n]=4/1`
`⇔ 2^n . 4 = 32.1`
`⇔ 2^n = 32 ÷ 4`
`⇔ 2^n = 8`
`⇔ 2^n = 2^3`
`⇔ n = 3`
`b, 8/[2^n] = 2`
`⇔ 8 = 2^n . 2`
`⇔ 2^3 = 2^[n+1]`
`⇔ 3 = n + 1`
`⇔ n = 2`
`c, (1/2)^{2n-1} = 1/8`
`⇔ (1/2)^{2n-1} = (1/2)^3`
`⇔ 2n – 1 = 3`
`⇔ 2n = 4`
`⇔ n = 2`
Xin hay nhất !