Đây nà…giúp mk nha, sắp ik học rồi ạ!!!
a) $(^{}$$3\frac{5}{7}$$x^{}$ $-^{}$ $1\frac{5}{7}$$x^{}$ $)^{}$ $-^{}$ $\frac{1}{3}$ $=^{}$ $\frac{2}{3}$
b) $(^{}$$\frac{4}{5}$$)^{2x+5}$ $=^{}$ $\frac{256}{625}$
Đây nà…giúp mk nha, sắp ik học rồi ạ!!!
a) $(^{}$$3\frac{5}{7}$$x^{}$ $-^{}$ $1\frac{5}{7}$$x^{}$ $)^{}$ $-^{}$ $\frac{1}{3}$ $=^{}$ $\frac{2}{3}$
b) $(^{}$$\frac{4}{5}$$)^{2x+5}$ $=^{}$ $\frac{256}{625}$
`a) => 2x – 1/3 = 2/3`
`=> 2x = 3/3`
`=> 2x = 1`
`=> x = 1/2`
`b) => (4/5)^(2x+5 ) = 256/625`
`=> (4/5)^(2x+5 ) = (4/5)^4`
`=> 2x+5 = 4 `
`=> 2x = -1`
`=> x = -1/2`
XIN HAY NHẤT Ạ
`a)(3 5/7 x-1 5/7 x)-1/3=2/3`
`→26/7 x – 12/7 x=1`
`→2x=1`
`→x=1/2`
Vậy `x=1/2`
`b)(4/5)^(2x+5)=256/625`
`→(4/5)^(2x+5)=(4/5)^4`
`→2x+5=4`
`→2x=4-5`
`→2x=-1`
`→x=-1/2`
Vậy `x=-1/2`