Toán 5.(x-1/2)-3.(x-1/4)=1 (1/3)^x+(1/3)^x+2=10/9 06/08/2021 By Savannah 5.(x-1/2)-3.(x-1/4)=1 (1/3)^x+(1/3)^x+2=10/9
`a) 5.(x-1/2)-3.(x-1/4)=1``=> 5x – 5/2 – 3x + 3/4 = 1``=> 5x – 3x = 1 + 5/2 – 3/4``=> 2x = 11/4``=> x = 11/4 : 2``=> x = 11/8`Vậy `x=11/8` `b) (1/3)^x+(1/3)^(x+2)=10/9``=> (1/3)^x + (1/3)^x . (1/3)^2 = 10/9``=> (1/3)^x + (1/3)^x . 1/9 = 10/9``=> (1/3)^x . (1+1/9) = 10/9``=> (1/3)^x . 10/9 = 10/9``=> (1/3)^x = 10/9 : 10/9``=> (1/3)^x = 1``=> (1/3)^x = (1/3)^0``=> x = 0`Vậy `x=0` Trả lời
Đáp án + Giải thích các bước giải: `5(x – 1/2) – 3(x – 1/4)=1` $\\$ `=>5x-5/2-3x+3/4=1` $\\$ `=> (5x – 3x) + (-5/2+3/4)=1` $\\$ `=> 2x – 7/4 = 1` $\\$ `=> 2x = 1 + 7/4 = 11/4` $\\$ `=> x = 11/4 : 2 = 11/8` Vậy `x = 11/8` Sửa đề : `(1/3)^x + (1/3)^(x+2)=10/9` $\\$ `=>(1/3)^x+(1/3)^x*(1/3)^2=10/9` $\\$ `=> (1/3)^x[1+(1/3)^2]=10/9` $\\$ `=> (1/3)^x(1 + 1/9) = 10/9` $\\$ `=> (1/3)^x*10/9 = 10/9` $\\$ `=> (1/3)^x = 1` $\\$ `=> x = 0` Vậy `x = 0` Trả lời
`a) 5.(x-1/2)-3.(x-1/4)=1`
`=> 5x – 5/2 – 3x + 3/4 = 1`
`=> 5x – 3x = 1 + 5/2 – 3/4`
`=> 2x = 11/4`
`=> x = 11/4 : 2`
`=> x = 11/8`
Vậy `x=11/8`
`b) (1/3)^x+(1/3)^(x+2)=10/9`
`=> (1/3)^x + (1/3)^x . (1/3)^2 = 10/9`
`=> (1/3)^x + (1/3)^x . 1/9 = 10/9`
`=> (1/3)^x . (1+1/9) = 10/9`
`=> (1/3)^x . 10/9 = 10/9`
`=> (1/3)^x = 10/9 : 10/9`
`=> (1/3)^x = 1`
`=> (1/3)^x = (1/3)^0`
`=> x = 0`
Vậy `x=0`
Đáp án + Giải thích các bước giải:
`5(x – 1/2) – 3(x – 1/4)=1` $\\$ `=>5x-5/2-3x+3/4=1` $\\$ `=> (5x – 3x) + (-5/2+3/4)=1` $\\$ `=> 2x – 7/4 = 1` $\\$ `=> 2x = 1 + 7/4 = 11/4` $\\$ `=> x = 11/4 : 2 = 11/8`
Vậy `x = 11/8`
Sửa đề : `(1/3)^x + (1/3)^(x+2)=10/9` $\\$ `=>(1/3)^x+(1/3)^x*(1/3)^2=10/9` $\\$ `=> (1/3)^x[1+(1/3)^2]=10/9` $\\$ `=> (1/3)^x(1 + 1/9) = 10/9` $\\$ `=> (1/3)^x*10/9 = 10/9` $\\$ `=> (1/3)^x = 1` $\\$ `=> x = 0`
Vậy `x = 0`