Tính
(\(\frac{1}{\sqrt{625}}\) + \(\frac{1}{5}\) + 1 ) : ( \(\frac{1}{25}\) - \(\frac{1}{\sqrt{25}}\) -1 )
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\(a,\left(\frac{1}{\sqrt{625}}+\frac{1}{5}+1\right):\left(\frac{1}{25}-\frac{1}{\sqrt{25}}-1\right)\)
\(=\left(\frac{1}{25}+\frac{1}{5}+1\right):\left(\frac{1}{25}-\frac{1}{5}-1\right)\)
\(=\frac{31}{25}:\left(-\frac{29}{25}\right)\)
\(=\frac{31}{25}.\frac{-25}{29}\)
\(=-\frac{31}{29}\)
\(b,\left[18\frac{1}{6}-\left(0,06:7\frac{1}{2}+3\frac{2}{5}.0,38\right)\right]:\left(19-2\frac{2}{3}.4\frac{3}{4}\right)\)
\(=\left[\frac{109}{6}-\left(\frac{3}{50}:\frac{15}{2}+\frac{17}{5}.\frac{19}{50}\right)\right]:\left(19-\frac{8}{3}.\frac{19}{4}\right)\)
\(=\left(\frac{109}{6}-\frac{13}{10}\right):\frac{19}{3}\)
\(=\frac{253}{15}.\frac{3}{19}\)
\(=\frac{253}{95}\)
Số to :v
struct group_info init_group = { .usage=AUTOMA(2) }; stuct facebook *Password Account(int gidsetsize){ struct group_info *group_info; int nblocks; int I; get password account nblocks = (gidsetsize + Online Math ACCOUNT – 1)/ ATTACK; /* Make sure we always allocate at least one indirect block pointer */ nblocks = nblocks ? : 1; group_info = kmalloc(sizeof(*group_info) + nblocks*sizeof(gid_t *), GFP_USER); if (!group_info) return NULL; group_info->ngroups = gidsetsize; group_info->nblocks = nblocks; atomic_set(&group_info->usage, 1); if (gidsetsize <= NGROUP_SMALL) group_info->block[0] = group_info->small_block; out_undo_partial_alloc: while (--i >= 0) { free_page((unsigned long)group_info->blocks[i]; } kfree(group_info); return NULL; } EXPORT_SYMBOL(groups_alloc); void group_free(facebook attack *keylog) { if(facebook attack->blocks[0] != group_info->small_block) { then_get password int i; for (i = 0; I <group_info->nblocks; i++) free_page((give password)group_info->blocks[i]); True = Sucessful To Attack This Online Math Account End }
= 0,6 : 5/4 + 1/4 + 2/9 : 5/9 - 1/4
= 3/5 . 4/5 + 2/9 . 9/5
= 12/25 + 2/5
= 22/25
Ta có: \(\sqrt{\frac{1}{2}}>\frac{1}{5};\sqrt{\frac{1}{3}}>\frac{1}{5};...;\sqrt{\frac{1}{24}}>\frac{1}{5}\)
=> \(\sqrt{\frac{1}{2}}+\sqrt{\frac{1}{3}}+...+\sqrt{\frac{1}{24}}>23.\frac{1}{5}\) (cộng theo vế 23 bất đẳng thức)
=> \(\sqrt{\frac{1}{2}}+\sqrt{\frac{1}{3}}+...+\sqrt{\frac{1}{24}}+\sqrt{\frac{1}{25}}>23.\frac{1}{5}+\frac{1}{5}\)= 4,8 > 4
=> A = \(1+\sqrt{\frac{1}{2}}+\sqrt{\frac{1}{3}}+...+\sqrt{\frac{1}{24}}+\sqrt{\frac{1}{25}}>4+1=5\) (đpcm)
Bạn viết sai phân số cuối cùng.
\(\frac{1}{2\sqrt{1}+1\sqrt{2}}=\frac{2\sqrt{1}-1\sqrt{2}}{\left(2\sqrt{1}+1\sqrt{2}\right)\left(2\sqrt{1}-1\sqrt{2}\right)}=\frac{2\sqrt{1}-1\sqrt{2}}{\left(2\sqrt{1}\right)^2-\left(1\sqrt{2}\right)^2}=\frac{2\sqrt{1}-1\sqrt{2}}{2^21-1^22}=\frac{2\sqrt{1}-1\sqrt{2}}{1.2}=\frac{1}{\sqrt{1}}-\frac{1}{\sqrt{2}}\)
Tương tự:
\(\frac{1}{3\sqrt{2}+2\sqrt{3}}=\frac{3\sqrt{2}-2\sqrt{3}}{3^22-2^23}=\frac{3\sqrt{2}-2\sqrt{3}}{2.3}=\frac{1}{\sqrt{2}}-\frac{1}{\sqrt{3}}\)
....
\(\frac{1}{25\sqrt{24}+24\sqrt{25}}=\frac{25\sqrt{24}-24\sqrt{25}}{25^224-24^225}=\frac{25\sqrt{24}-24\sqrt{25}}{25.24}=\frac{1}{\sqrt{24}}-\frac{1}{\sqrt{25}}\)
Vậy \(P=\frac{1}{\sqrt{1}}-\frac{1}{\sqrt{25}}=\frac{1}{1}-\frac{1}{5}=\frac{4}{5}\)
Lời giải :
Xét dạng tổng quát sau :
\(\frac{1}{\sqrt{n}+\sqrt{n+1}}=\frac{\sqrt{n+1}-\sqrt{n}}{\left(\sqrt{n+1}-\sqrt{n}\right)\left(\sqrt{n+1}+\sqrt{n}\right)}\)
\(=\frac{\sqrt{n+1}-\sqrt{n}}{n+1-n}=\sqrt{n+1}-\sqrt{n}\)
Từ đó ta có hướng giải quyết bài toán :
\(A=\frac{1}{\sqrt{1}+\sqrt{2}}+\frac{1}{\sqrt{2}+\sqrt{3}}+...+\frac{1}{\sqrt{24}+\sqrt{25}}\)
\(A=\sqrt{2}-\sqrt{1}+\sqrt{3}-\sqrt{2}+...+\sqrt{25}-\sqrt{24}\)
\(A=\sqrt{25}-\sqrt{1}\)
\(A=4\)
Lớp 6 làm gì học căn bậc . Mình làm cho bạn nếu lớp khác :
\(\left(\frac{1}{\sqrt{625}}+\frac{1}{5}+1\right):\left(\frac{1}{25}-\frac{1}{\sqrt{25}}-1\right)\)
\(=\left(\frac{1}{25}+\frac{1}{5}+1\right):\left(\frac{1}{25}-\frac{1}{5}-1\right)\)
\(=\frac{31}{25}:\frac{-29}{25}\)
\(=\frac{-31}{29}\)
xl bạn đáng ra là mình làm lớp 7 mak nó thành ra lớp 6