tìm số nguyên x biết ( - 400 ) : 20 + 5 . ( 4 x - 1 ) = 15
2 câu trả lời
`(-400) : 20 + 5.(4x - 1) =15`
`=> (-20) + 5.(4x - 1) = 15`
`=> 5.(4x - 1) = 15 - (-20)`
`=> 5.(4x - 1) = 35`
`=> 4x - 1 = 35 : 5`
`=> 4x - 1 = 7`
`=> 4x = 7 + 1`
`=> 4x = 8`
`=> x =8 : 4`
`=> x = 2`
Vậy `x = 2`
`#dtkc`
`@` Tham khảo `@`
`(-400):20+5.(4x-1)= 15`
`(-20)+5.(4x-1)= 15`
`5.(4x-1)= 15-(-20)`
`5.(4x-1)= 15+20`
`5.(4x-1)= 35`
`4x-1= 35:5`
`4x-1= 7`
`4x= 7+1`
`4x= 8`
`x= 8:4`
`x= 2`
Vậy `x= 2`
`#Jo`