Tìm x :
( x + 2/3 ) + ( x + 2/15 ) + ( x + 2/35 ) + ( x + 2/63 ) = 8/9
Tìm x : ( x + 2/3 ) + ( x + 2/15 ) + ( x + 2/35 ) + ( x + 2/63 ) = 8/9
By Melanie
By Melanie
Tìm x :
( x + 2/3 ) + ( x + 2/15 ) + ( x + 2/35 ) + ( x + 2/63 ) = 8/9
Đáp án + Giải thích các bước giải:
`(x+2/3)+(x+2/15)+(x+2/35)+(x+2/63)=8/9`
`x+2/3+x+2/15+x+2/35+x+2/63-8/9=0`
`(x+x+x+x)+(2/3+2/15+2/35+2/63-8/9)=0`
`4xxx+(2/(1xx3)+2/(3xx5)+2/(5xx7)+2/(7xx9)-8/9)=0`
`4xxx+(1-1/3+1/3-1/5+1/5-1/7+1/7-1/9-8/9)=0`
`4xxx+(1-1/9-8/9)=0`
`4xxx+(9/9-1/9-8/9)=0`
`4xxx+0=0`
`4xxx=0-0`
`4xxx=0`
`x=0:4`
`x=0`
Đáp án + Giải thích các bước giải:
`(x + \frac{2}{3}) + (x + \frac{2}{15}) + (x + \frac{2}{35}) + (x + \frac{2}{63}) = \frac{8}{9}`
`(x + 1 – \frac{1}{3}) + (x + \frac{1}{3} – \frac{1}{5}) + (x + \frac{1}{5} – \frac{1}{7}) + (x + \frac{1}{7} – \frac{1}{9}) = \frac{8}{9}`
`x + 1 – \frac{1}{3} + x + \frac{1}{3} – \frac{1}{5} + x + \frac{1}{5} – \frac{1}{7} + x + \frac{1}{7} – \frac{1}{9} = \frac{8}{9}`
`4x + 1 – \frac{1}{9} = \frac{8}{9}`
`4x + 1 = \frac{8}{9} + \frac{1}{9}`
`4x + 1 = 1`
`4x = 0`
`x = 0`