Ai nhanh mik tik
12 × (7/6 - 8/12 + 29/4)
Dấu / là dấu phân số
Có bạn là nhanh nha vì đề bài là tính thuận tiện
Hãy nhập câu hỏi của bạn vào đây, nếu là tài khoản VIP, bạn sẽ được ưu tiên trả lời.
35 x 25 x 7 x 8 = 49 000
74 x 8 x 12 x 14 = 99 456
_HT_
a. 100 - 7 ( x - 5 ) = 58
<=> 7 ( x - 5 ) = 100 - 58
<=> 7 ( x - 5 ) = 42
<=> x - 5 = 42 : 7
<=> x - 5 = 6
<=> x = 6 + 5
<=> x = 11
Tương tự tiếp.
a;100-7(x-5)=58
=>7(x-5)=100-58=42
=>x-5=42:7=6
=>x=6+5=11
b;12(x-1):3=72
=>12(x-1)=72.3=216
=>x-1=216:12=18
=>x=18+1=19
c;12-4(x-1)=4
=>4(x-1)=12-4=8
=>x-1=8:4=2
=>x=2+1=3
d;32-12x=8
=>12x=32-8=24
=>x=24:12=2
nho h do nhe viet moi tay lam day biet ko
5/6+3/4 < 19/11 4/9 x 6/5 = 8/15
17/12-9/8 < 1/3 15/4:3/8 > 8
Ta có: \(\frac{5}{6}+\frac{3}{4}=\frac{10}{12}+\frac{9}{12}=\frac{19}{12}\)
Vì \(12>11\)
\(\Rightarrow\frac{19}{12}< \frac{19}{11}\)
\(\Rightarrow\frac{5}{6}+\frac{3}{4}< \frac{19}{11}\)
Ta có: \(\frac{17}{12}-\frac{9}{8}=\frac{34}{24}-\frac{27}{24}=\frac{7}{24}\)
Ta lại có: \(\frac{1}{3}=\frac{8}{24}\)
Vì \(8>7\)
\(\Rightarrow\frac{7}{24}< \frac{8}{24}\)
\(\Rightarrow\frac{17}{12}-\frac{9}{8}< \frac{1}{3}\)
Ta có: \(\frac{4}{9}\times\frac{6}{5}=\frac{24}{45}=\frac{8}{15}\)
Vì \(\frac{8}{15}=\frac{8}{15}\)
\(\Rightarrow\frac{4}{9}\times\frac{6}{5}=\frac{8}{15}\)
Ta có: \(\frac{15}{4}:\frac{3}{8}=\frac{15}{4}\times\frac{8}{3}=10\)
Vì \(10>8\)
\(\Rightarrow\frac{15}{4}:\frac{3}{8}>8\)
HOK TOT
a)[(-7)+(-93)]+[(-125)+(-25)
=-100+-150
=-250
b)2012+(-1000)+(-12)+(-500)
=[2012+(-12)]+[(-1000)+(-500)]
=2000+-1500
=-500
c)(-12).7+(-8).7+4.(-25)+(-6).(-25)
=7[(-12)+(-8)]+-25[4+-6]
=7.(-20)+-25.-2
=-140+50
=-90
a) (-7) + (-125) + (-93) + (-25)
= -7 - 125 - 93 - 25
= (-7 - 93) - (125 + 25)
= -100 + (-150)
= -250
b) 2012 + (-1000) + (-12) + (-500)
= (2012 - 12) - (1000 + 500)
= 2000 - 1500
= 500
c) (-12).7 + (-8).7 + 4.(-25) + (-6) . (-25)
= (-12 + (-8) . 7 + (4 + (-6) . (-25)
= -20 .7 + (-2) . (-25)
= -2 . 10 . 7 + (-2) . 25
= -2 . 70 + (-2) . 25
= -2 . (70 + 25)
= -2 . 95
= -190
a) 6 + 2 x 64 x 3 + 4 x 36
= 6 + 6 x 64 + 4 x 6 x 6
= 6 + 6 x 64 + 6 x 24
= 6 x (1 + 64 + 24)
= 6 x 89
= 534
b) 4 + 6 + 12 + ... + 2008 + 2012
= 2 x (2 + 3 + 4 + ... + 1004 + 1005)
= 2 x (2 + 1005) x 1004 : 2
= 1007 x 1004
= 1011028
\(a,=\frac{7-1}{1.3.7}+\frac{9-3}{3.7.9}+\frac{13-7}{7.9.13}+\frac{15-9}{9.13.15}\)\(+\frac{19-13}{13.15.19}\)
\(=\frac{1}{1.3}-\frac{1}{3.7}+\frac{1}{3.7}-\frac{1}{7.9}+\frac{1}{7.9}-\frac{1}{9.13}+\frac{1}{9.13}-\frac{1}{13.15}+\frac{1}{13.15}-\frac{1}{15.19}\)
\(=\frac{1}{1.3}-\frac{1}{15.19}=\frac{95}{285}-\frac{1}{285}=\frac{94}{285}\)
\(b,=\frac{1}{6}.\left(\frac{6}{1.3.7}+\frac{6}{3.7.9}+\frac{6}{7.9.13}+\frac{6}{9.13.15}+\frac{6}{13.15.19}\right)\)
làm giống như trên
\(c,=\frac{1}{8}.\left(\frac{1}{1.2.3}+\frac{1}{2.3.4}+\frac{1}{3.4.5}+...+\frac{1}{48.49.50}\right)\)
\(=\frac{1}{16}.\left(\frac{2}{1.2.3}+\frac{2}{2.3.4}+\frac{2}{3.4.5}+...+\frac{2}{48.49.50}\right)\)
\(=\frac{1}{16}.\left(\frac{3-1}{1.2.3}+\frac{4-2}{2.3.4}+\frac{5-3}{3.4.5}+...+\frac{50-48}{48.49.50}\right)\)
\(=\frac{1}{16}.\left(\frac{1}{1.2}-\frac{1}{2.3}+\frac{1}{2.3}-\frac{1}{3.4}+\frac{1}{3.4}-\frac{1}{4.5}+...+\frac{1}{48.49}-\frac{1}{49.50}\right)\)
\(=\frac{1}{16}.\left(\frac{1}{2}-\frac{1}{2450}\right)=\frac{1}{16}.\left(\frac{1225}{2450}-\frac{1}{2450}\right)=\frac{153}{4900}\)
\(d,=\frac{5}{7}.\left(\frac{7}{1.5.8}+\frac{7}{5.8.12}+\frac{7}{8.12.15}+...+\frac{7}{33.36.40}\right)\)
\(=\frac{5}{7}.\left(\frac{8-1}{1.5.8}+\frac{12-5}{5.8.12}+\frac{15-8}{8.12.15}+...+\frac{40-33}{33.36.40}\right)\)
\(=\frac{5}{7}.\left(\frac{1}{1.5}-\frac{1}{5.8}+\frac{1}{5.8}-\frac{1}{8.12}+\frac{1}{8.12}-\frac{1}{12.15}+...+\frac{1}{33.36}-\frac{1}{36.40}\right)\)
\(=\frac{5}{7}.\left(\frac{1}{5}-\frac{1}{1440}\right)=\frac{5}{7}.\left(\frac{288}{1440}-\frac{1}{1440}\right)=\frac{41}{288}\)
P/S: . là nhân nha
1a) \(\frac{49}{84}-\frac{24}{84}+\frac{7}{84}\)
\(=\frac{8}{21}\)
2b)\(=\frac{72}{99}-\left(\frac{28}{99}+\frac{14}{99}\right)\)
\(=\frac{72}{99}-\frac{42}{99}\)
=\(\frac{30}{99}=\frac{10}{33}\)
c) = 83,45 - ( 30,98 + 42,47 )
= 83,45 - 73,45
= 10
mình làm được rồi đấy nhớ k cho mình nhe
7/12-2/7+1/12
=49/84-24/84+7/84
=73/84-7/84
=66/84=22/28
2.
a)72/99-28/99-14/99
=72/99-(28/99+14/99)
=72/99-42/99
=30/99=10/33
83,45-30,98-42,47
=83,45-(30,98+42,47)
=83,45-73,45
=10
\(12.\left(\frac{7}{6}-\frac{8}{12}+\frac{29}{4}\right)\)
\(=12.\left(\frac{14}{12}-\frac{8}{12}+\frac{29}{4}\right)\)
\(=12.\left(\frac{6}{12}+\frac{29}{4}\right)\)
\(=12.\left(\frac{2}{4}+\frac{29}{4}\right)\)
\(=12.\frac{31}{4}\)
\(=93\)
Chúc bạn học tốt !!!
\(93\)