tính hợp lí:2^7x9^2/3^3x2^5
\(\frac{2^7x9^2}{3^3x2^5}\) giúp mik
đây là tìm x hay tính toán vậy
=\(\frac{2^52^2x3^4}{3^3x2^5}\)=\(\frac{2^23^33}{3^3}\)=4.3=12
\(\frac{2^7\cdot9^2}{3^3\cdot2^5}=\frac{2^7\cdot\left(3^2\right)^2}{3^3\cdot2^5}=\frac{2^7\cdot3^4}{3^3\cdot2^5}=2^2\cdot3=4\cdot3=12\)
Vậy \(\frac{2^7\cdot9^3}{3^3\cdot2^5}=12\)
Tính tổng sau bằng cách hợp lí:
A = 2/1x3 + 2/3x5 + 2/5x7 + 2/7x9 + 2/9x11
Ta có:
A = \(\frac{2}{1x3}+\frac{2}{3x5}+\frac{2}{5x7}+\frac{2}{7x9}+\frac{2}{9x11}\)
= \(\frac{1}{1}-\frac{1}{3}+\frac{1}{3}-\frac{1}{5}+\frac{1}{5}-\frac{1}{7}+\frac{1}{7}-\frac{1}{9}+\frac{1}{9}-\frac{1}{11}\)
= \(\frac{1}{1}-\frac{1}{11}\)
=\(\frac{10}{11}\)
thực hiện phép tính bằng cách hợp lí (nếu có thể)
a,136:{[(468+332):160-5]+68}+2014
b,160-(6x5^2-3x2^3)+2015^0
thực hiện phép tính bằng cách hợp lí (nếu có thể)
a,136:{[(468+332):160-5]+68}+2014
= 136 : { [ ( 468 + 332 ) : 160 - 5 ] + 68 } + 2014
= 136 : { [ 800 : 160 - 5 ] + 68 } + 2014
= 136 : { [ 5 - 5 ] + 68 } + 2014
= 136 : { 0 + 68 } + 2014
= 136 : 68 + 2014
= 2 + 2014
= 2016
\(136:\left\{\left[\left(468+332\right):160-5\right]+68\right\}+2014\)
\(=136:\left[\left(800:160-5\right)+68\right]+2014\)
\(=136:\left[\left(5-5\right)+68\right]+2014\)
\(=136:\left(0+68\right)+2014\)
\(=136:68+2014=2+2014\)
\(=2016\)
\(136:\left\{\left[\left(468+332\right):160-5\right]+68\right\}+2014\)
\(=136:\left\{\left[800:160-5\right]+68\right\}+2014\)
\(=136:\left\{\left[5-5\right]+68\right\}+2014\)
\(=136:\left\{0+68\right\}+2014\)
\(=136:68+2014\)
\(=2+2014\)
\(=2016\)
a) \(\left(-\frac{1}{7}\right)^0-2\frac{4}{9}x\left(-\frac{2}{3}\right)^2\); b) \(\frac{2^7x9^2}{3^3x2^5}\).
b, Ta có : \(\frac{2^7x9^2}{3^3x2^5}=\frac{2^52^2x3^23.3}{3.3^2x2^5}=\frac{2^2x3}{x}=12\)
tính hợp lí theo các bài toán sau:
a)12+4x12+5
b)8x5+8x4+8x6
c)2+3x2+4x2+6
May tinh la hop li thuan tien nhat nha bn
a) = 4x ( 12 + 1 ) +5
= 4 x 13 + 5
= 57
b)= (8x4 + 8x6) +8x 5
= 8x 10 + 8x5
= 80 + 40
= 120
c) = 2 + 3x2 + 4x2 + 3x2
= 2 + ( 2 x 10 )
= 2 + 20
= 22
hiểu ý giang ho dai ca roi
bạn quý chết thì có
(1/2-2/3)-(5/3-3/2)+(7/3-5/2),tính hợp lí
(1/2-2/3)-(5/3-3/2)+(7/3-5/2)
=1/2-2/3-5/3+3/2+7/3-5/2
=(1/2+3/2-5/2)-(2/3+5/3-7/3)
=-1/2-0=-1/2
Tính hợp lí -2/5 × 4/7 + -3/5 × 2/7 + -3/5
\(-\dfrac{2}{5}.\dfrac{4}{7}+\dfrac{-3}{5}.\dfrac{2}{7}+\dfrac{-3}{5}\)
= \(\dfrac{-8}{35}+\dfrac{-6}{35}+\dfrac{-3}{5}\)
=\(\dfrac{-8-6-21}{35}\)
=\(\dfrac{-35}{35}\)
=-1
`(-2)/5.4/7+(-3)/5.2/7+(-3)/5`
`=(-8)/3 +(-6)/35+(-3)/5`
`=(-8)-6-21/35`
`=(-35)/35`
`=(-1)`
`@Nae`
(-2)/5 x 4/7 + (-3)/5 x 2/7 + (-3)/5
`=(-8)/3 +(-6)/35+(-3)/5`
`=(-8)-6-21/35`
`=(-35)/35`
`=(-1)`
`@Nae`
Tính
a. 3/(3x5) + 3/(5x7) + 3/(7x9) +... + 3/(99x101)
b. 5/(3x5) +5/(5x7) +5/(7x9) +...+ 5/(99x101)
917749738461936926399639748776398646491639394748947630373937366
Tính hợp lí:
3/5×(5/2 - 10/3) - 5/8 : (1/4-2/3)
\(\dfrac{3}{5}\) \(\times\) ( \(\dfrac{5}{2}\) - \(\dfrac{10}{3}\)) - \(\dfrac{5}{8}\): ( \(\dfrac{1}{4}\) - \(\dfrac{2}{3}\))
\(\dfrac{3}{5}\) \(\times\) \(\dfrac{5}{2}\) - \(\dfrac{3}{5}\) \(\times\) \(\dfrac{10}{3}\) - \(\dfrac{5}{8}\): (-\(\dfrac{5}{12}\))
= \(\dfrac{3}{2}\) - 2 + \(\dfrac{3}{2}\)
= (\(\dfrac{3}{2}\) + \(\dfrac{3}{2}\)) - 2
= 3 - 2
= 1