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222-9+11+12:2*14+14 = ? ( )

Toán Lớp 6: a)196:4-12.(-15) b)2^2.5+(49-17^2 c)29.(15-34)-15.(29-34) d)(705-x):3=4221:21 e)100-7(x-5)=58 g)(2x-1)^3=125 h)Cho tổng A=2^0+2^1+2^2+2

Tháng Năm 7, 2023 Toán học 1 Comment 0 views

Toán Lớp 6: a)196:4-12.(-15)
b)2^2.5+(49-17^2
c)29.(15-34)-15.(29-34)
d)(705-x):3=4221:21
e)100-7(x-5)=58
g)(2x-1)^3=125
h)Cho tổng A=2^0+2^1+2^2+2^3+2^4+2^5+….+2^100

Comments ( 1 )

  1. dongoclandiem
    dongoclandiem
    7 Tháng Năm, 2023 at 4:36 sáng
    Reply
    $\text{a}$$\text{,}$ $\text{196}$ $\text{:}$ $\text{4}$ $\text{-}$ $\text{12}$ $\text{.}$ $\text{(-15)}$
    $\text{=}$ $\text{49}$ + $\text{12}$ $\text{.}$ $\text{15}$
    $\text{=}$ $\text{49}$ $\text{+}$ $\text{180}$
    $\text{=}$ $\text{229}$ 
    $\text{b}$$\text{,}$ $\text{2^2}$ $\text{.}$ $\text{5}$ $\text{+}$ $\text{(}$$\text{49}$ $\text{-}$ $\text{17^2}$$\text{)}$
    $\text{=}$ $\text{4}$ $\text{.}$ $\text{5}$ $\text{+}$ $\text{(}$$\text{49}$ $\text{-}$ $\text{289}$$\text{)}$
    $\text{=}$ $\text{20}$ $\text{+}$ $\text{(}$$\text{-240}$$\text{)}$
    $\text{=}$ $\text{20}$ $\text{-}$ $\text{240}$
    $\text{=}$ $\text{-220}$
    $\text{c}$$\text{,}$ $\text{29.(15 – 34) – 15.(29 – 34)}$
    $\text{=}$ $\text{29.15 – 29.34 – 15.29 + 15.34}$
    $\text{=}$ $\text{- 29.34 + 15.34}$
    $\text{=}$ $\text{(- 29 + 15).34}$
    $\text{=}$ $\text{(- 14).34}$
    $\text{=}$ $\text{- 476}$
    $\text{d}$$\text{,}$ $\text{(705 – x):3= 4221:21}$
    $\Rightarrow$ $\text{705 – x= 4221:7}$
    $\Rightarrow$ $\text{705 – x= 603}$
    $\Rightarrow$ $\text{x= 705-603}$
    $\Rightarrow$ $\text{x= 102}$
    $\text{e, 100 – 7(x – 5) = 58}$
    $\text{$\Rightarrow$ 7(x – 5) = 100 – 58}$
    $\text{$\Rightarrow$ 7(x – 5) = 42}$
    $\text{$\Rightarrow$ x – 5 = 6}$
    $\text{$\Rightarrow$ x = 11}$
    $\text{g, $(2x – 1)^3$ = 125}$
    $\text{$\Rightarrow$ $(2x – 1)^3$ = $5^3$}$
    $\text{$\Rightarrow$ 2x – 1 = 5 }$
    $\text{$\Rightarrow$ 2x = 6 }$
    $\text{$\Rightarrow$ x = 3 }$
    $\text{h, A = $2^0$ + $2^1$ + $2^2$ + ….. + $2^{99}$ + $2^{100}$}$
    $\text{$\Rightarrow$ 2A = $2^1$ + $2^2$ + $2^3$ + ….. + $2^{100}$ + $2^{101}$}$
    $\text{$\Rightarrow$ A = 2A – A = ($2^1$ + $2^2$ + $2^3$ + ….. + $2^{100}$ + $2^{101}$) – ($2^0$ + $2^1$ + $2^2$ + ….. + $2^{99}$ + $2^{100}$) }$
    $\text{$\Rightarrow$ A = 2A – A = $2^{101}$ – $2^0$ = $2^{101}$ – 1 }$

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222-9+11+12:2*14+14 = ? ( )

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