a) (x+2)+(x+4)+(x+6)+(x+8)=36 b) (3/4 +x)*50%=0,8 24/07/2021 Bởi Adeline a) (x+2)+(x+4)+(x+6)+(x+8)=36 b) (3/4 +x)*50%=0,8
Đáp án: `a)x=4` `b)x=17/20` Giải thích các bước giải: `a)(x+2)+(x+4)+(x+6)+(x+8)=36` `x+2+x+4+x+6+x+8` `=36` `4×x+20` `=36` `4×x` `=36-20` `4×x` `=16` `x` `=16:4` `x` `=4` `b)(3/4+x)×50%=0,8` `(3/4+x)×1/2` `=4/5` `3/4+x` `=4/5:1/2` `3/4+x` `=4/5×2` `3/4+x` `=8/5` `x` `=8/5-3/4` `x` `=32/20-15/20` `x` `=17/20` Bình luận
a) `(x+2)+(x+4)+(x+6)+(x+8)=386` `⇔x+2+x+4+x+6+x+8=36` `⇔4×x+20=36` `⇔4×x=36-20` `⇔4×x=16` `⇔x=4` b) `(3/4+x)×0,5=0,8` `⇔3/4+x=0,8:0,5` `⇔3/4+x=1,6` `⇔3/4+x=8/5` `⇔x=8/5 – 3/4` `⇔x=17/20` Vậy `x=17/20` `#IQ` Bình luận
Đáp án:
`a)x=4`
`b)x=17/20`
Giải thích các bước giải:
`a)(x+2)+(x+4)+(x+6)+(x+8)=36`
`x+2+x+4+x+6+x+8` `=36`
`4×x+20` `=36`
`4×x` `=36-20`
`4×x` `=16`
`x` `=16:4`
`x` `=4`
`b)(3/4+x)×50%=0,8`
`(3/4+x)×1/2` `=4/5`
`3/4+x` `=4/5:1/2`
`3/4+x` `=4/5×2`
`3/4+x` `=8/5`
`x` `=8/5-3/4`
`x` `=32/20-15/20`
`x` `=17/20`
a) `(x+2)+(x+4)+(x+6)+(x+8)=386`
`⇔x+2+x+4+x+6+x+8=36`
`⇔4×x+20=36`
`⇔4×x=36-20`
`⇔4×x=16`
`⇔x=4`
b) `(3/4+x)×0,5=0,8`
`⇔3/4+x=0,8:0,5`
`⇔3/4+x=1,6`
`⇔3/4+x=8/5`
`⇔x=8/5 – 3/4`
`⇔x=17/20`
Vậy `x=17/20`
`#IQ`