giải pt 69-x/1942 + 67-x/1944 + 65-x/1946 + 63-x/1948 + 61-x/1950 =-5 22/10/2021 Bởi Lyla giải pt 69-x/1942 + 67-x/1944 + 65-x/1946 + 63-x/1948 + 61-x/1950 =-5
`(69-x)/1942 + (67-x)/1944 + (65-x)/1946 + (63-x)/1948 + (61-x)/1950 =-5` `⇔(69-x)/1942 + 1 + (67-x)/1944 + 1 + (65-x)/1946 + 1 + (63-x)/1948 + 1+ (61-x)/1950 +1 = 0` `⇔(69-x+1942)/1942+(67-x+1944)/1944 + (65-x+1946)/1946 + (63-x+1948)/1948 + (61-x+1950)/1950=0` `⇔(2011-x)/1942+(2011-x)/1944+(2011-x)/1946+(2011-x)/1948+(2011-x)/1950=0` `⇔(2011-x)(1/1942+1/1944+1/1946+1/1948+1/1950)=0` `⇔2011-x=0` `⇔x=2011` Bình luận
Đáp án: Giải thích các bước giải: `(69-x)/1942 + (67-x)/1944 + (65-x)/1946 + (63-x)/1948 + (61-x)/1950 =-5` `<=>((69-x)/1942+1) + ((67-x)/1944+1) + ((65-x)/1946+1) + ((63-x)/1948+1) + ((61-x)/1950+1) =0` `<=>(2011-x)/1942 + (2011-x)/1944 + (2011-x)/1946 + (2011-x)/1948 + (2011-x)/1950 =0` `<=>(2011-x)(1/1942 + 1/1944 + 1/1946 +1/1948 + 1/1950 ) =0` mà `1/1942 + 1/1944 + 1/1946 +1/1948 + 1/1950 ne0` `<=>2011-x=0` `<=>x=2011` Bình luận
`(69-x)/1942 + (67-x)/1944 + (65-x)/1946 + (63-x)/1948 + (61-x)/1950 =-5`
`⇔(69-x)/1942 + 1 + (67-x)/1944 + 1 + (65-x)/1946 + 1 + (63-x)/1948 + 1+ (61-x)/1950 +1 = 0`
`⇔(69-x+1942)/1942+(67-x+1944)/1944 + (65-x+1946)/1946 + (63-x+1948)/1948 + (61-x+1950)/1950=0`
`⇔(2011-x)/1942+(2011-x)/1944+(2011-x)/1946+(2011-x)/1948+(2011-x)/1950=0`
`⇔(2011-x)(1/1942+1/1944+1/1946+1/1948+1/1950)=0`
`⇔2011-x=0`
`⇔x=2011`
Đáp án:
Giải thích các bước giải:
`(69-x)/1942 + (67-x)/1944 + (65-x)/1946 + (63-x)/1948 + (61-x)/1950 =-5`
`<=>((69-x)/1942+1) + ((67-x)/1944+1) + ((65-x)/1946+1) + ((63-x)/1948+1) + ((61-x)/1950+1) =0`
`<=>(2011-x)/1942 + (2011-x)/1944 + (2011-x)/1946 + (2011-x)/1948 + (2011-x)/1950 =0`
`<=>(2011-x)(1/1942 + 1/1944 + 1/1946 +1/1948 + 1/1950 ) =0`
mà `1/1942 + 1/1944 + 1/1946 +1/1948 + 1/1950 ne0`
`<=>2011-x=0`
`<=>x=2011`