Câu 7: A=7+(7/12-1/2+3)- (1/12+5) cÂU 8: A=-1/4+7/33 -5/3-(-15/12+6/11-68/49)
Câu a7/8 chia đóng ngoặc 2/9 - 18 đóng ngoặc + 7/8 x 1/36 - 5/12 câu b 3/7 x 4/9 + 3/7 x 5/9 chia 6/12 câu c 5^8 x 16/31 - 5^8 x 47/31 + 1/3 câu d 7/2 x 3/8 + 7/2 x 5/8 chia 4/15
a: =7/8:(2/9-18+1/36)-5/12
=-7/142-5/12=-397/852
b: =3/7(4/9+5/9:6/12)=2/3
c: =5^8(16/31-47/31)+1/3=-5^8+1/3
d: =7/2(3/8+5/8:4/15)=609/64
Câu 1 : đúng ghi Đ , sai ghi S vào chỗ trống
H) 16/37 = 32/74
I) 105/111 = 420/444
Câu 2: dãy các phân số được sắp xếp theo thứ tự từ lớn đến bé là :
a) A. 1/2 ; 2/3 ; 4/5 ; 5/6 ; 7/12 B.5/6 ; 4/5 ; 2/3 ; 7/12 ; 1/2
C.7/12 ; 4/5 ; 5/6 ; 2/3 ; 1/2
b) A.1/2 ; 2/3 ; 3/7 B.3/7 ; 2/3 ; 1/2 C.2/3 ; 1/2 ; 3/7 D.2/3 ; 3/7 ; 1/2
Câu hỏi : a) 1/7 + 2/7 + 3/7 + 4/7 + 5/7 + 6/7 = ?
b) 1/2 + 2/4 + 3/6 + 4/8 + 5/10 + 6/12 = ?
Bạn nào trả lời mình like cho. Mình cần gấp
a) 1/7 + 2/7 + 3/7 + 4/7 + 5/7 +6/7 = 3
b) 1/2 + 2/4 + 3/6 + 4/8 + 5/10 + 6/12 = 3
câu a bằng 3 nha
câu b cũng bằng 3 nha
a,\(\frac{1}{7}+\frac{2}{7}+\frac{3}{7}+\frac{4}{7}+\frac{5}{7}+\frac{6}{7}=\frac{1+2+3+4+5+6}{7}\)\(=\)\(\frac{21}{7}\)
b,\(\frac{1}{2}+\frac{2}{4}+\frac{3}{6}+\frac{4}{8}+\frac{5}{10}+\frac{6}{12}\)\(=\)\(\frac{1}{2}+\frac{1}{2}+\frac{1}{2}+\frac{1}{2}+\frac{1}{2}+\frac{1}{2}\)\(=\)\(\frac{1+1+1+1+1+1}{2}\)\(=\)\(\frac{6}{2}=6\div2=3\)
Câu 1. -12+(16-11).4 Câu 2: hỗn số 2 3/7+1 4/7 câu 3: -2/3.4/5+1/5:9/11
Câu 1:
\(-12+\left(16-11\right).4=-12+5.4=-12+20=8\)
Câu 2:
\(2\dfrac{3}{7}+1\dfrac{4}{7}=\dfrac{17}{7}+\dfrac{11}{7}=\dfrac{17+11}{7}=\dfrac{28}{7}=4\)
Câu 3:
\(\dfrac{-2}{3}.\dfrac{4}{5}+\dfrac{1}{5}:\dfrac{9}{11}=\dfrac{-8}{15}+\dfrac{11}{45}=\dfrac{-13}{45}\)
Câu 1:
\(-12+\left(16-11\right).4=-12+5.4=-12+20=8\)
Câu 2:
\(2\dfrac{3}{7}+1\dfrac{4}{7}=\dfrac{17}{7}+\dfrac{11}{7}=\dfrac{28}{7}=4\)
Câu 3:
\(\dfrac{-2}{3}.\dfrac{4}{5}+\dfrac{1}{5}:\dfrac{9}{11}=\dfrac{-8}{15}+\dfrac{1}{5}.\dfrac{11}{9}=\dfrac{-8}{15}+\dfrac{11}{45}=\dfrac{-13}{45}\)
mọi người cho mk hỏi câu : A = 2/7+ -3/8 +11/7+ 1/3+ 1/7+ 5/-8;
B= -3/8+ 12/25+ 5/-8 +2/-5 +13/25
mong mọi người giúp...
a) Ta có: \(A=\dfrac{2}{7}+\dfrac{-3}{8}+\dfrac{11}{7}+\dfrac{1}{3}+\dfrac{1}{7}+\dfrac{5}{-8}\)
\(=\left(\dfrac{2}{7}+\dfrac{11}{7}+\dfrac{1}{7}\right)+\left(\dfrac{-3}{8}+\dfrac{-5}{8}\right)+\dfrac{1}{3}\)
\(=2-1+\dfrac{1}{3}\)
\(=1+\dfrac{1}{3}=\dfrac{4}{3}\)
b) Ta có: \(B=\dfrac{-3}{8}+\dfrac{12}{25}+\dfrac{5}{-8}+\dfrac{2}{-5}+\dfrac{13}{25}\)
\(=\left(\dfrac{-3}{8}+\dfrac{-5}{8}\right)+\left(\dfrac{12}{25}+\dfrac{13}{25}\right)+\dfrac{-2}{5}\)
\(=-1+1+\dfrac{-2}{5}\)
\(=-\dfrac{2}{5}\)
Giải:
A= 2/7+ -3/8 +11/7 +1/3 + 1/7 + 5/-8
A= (2/7+11/7+1/7)+(-3/8+-5/8)+1/3
A= 2+ (-1) + 1/3
A= 1+1/3
A= 4/3
B= -3/8 + 12/25 + 5/-8 + 2/-5 + 13/25
B= (-3/8+-5/8) + (12/25+13/25) + -2/5
B= -1 + 1 + -2/5
B=-2/5
Chúc bạn học tốt!
a) Ta có: =(2/7+11/7+1/7)+(−3/8+−5/8)+1/3
=1+1/3=4/3
b) Ta có: =(−3/8+−5/8)+(12/25+13/25)+−2/5
=−2/5
Câu 1 Tính :
a) (-1/4+7/33-5/3)-(-15/12+6/11-48/49)
b)167*54-167*55/167*252-167*55
Câu 2) tìm giá trị lớn nhất của A = 12- |x+4|
1, Thực hiện phép tính ( tính hợp lý nếu có thể) A, -1/12+4/3 B,(-4/14-3/15)-(1/5-20/35- -1)7 C, 3/5+ -5/20+30/75+ -7/4 D, 5/6. -12/13 + 7/13 E, 2/-9 - 5/-36 - 1/4 F, 2/23 +-5/12+7/18+21/23+ -7/12
c) Ta có: \(\dfrac{3}{5}+\dfrac{-5}{20}+\dfrac{30}{75}+\dfrac{-7}{4}\)
\(=\dfrac{3}{5}+\dfrac{2}{5}+\dfrac{-1}{4}+\dfrac{-7}{4}\)
\(=1-2=-1\)
Giải:
a)-1/12+4/3=-1/12+16/12=15/12=5/4
b)(-4/14-3/15)-(1/5-20/35-(-1)).7
=-17/35-22/35.7
=-17/35-22/5
=-171/35
c)3/5+-5/20+30/75+-7/4
=3/5+-1/4+2/5+-7/4
=(3/5+2/5)+(-1/4+-7/4)
=1+-2
=-1
d)5/6.-12/14+7/13
=-5/7+7/13
=-16/91
e)2/-9-5/-36-1/4
=-1/12-1/4
=-1/3
f)2/23+-5/12+7/18+21/23+-7/12
=(2/23+21/23)+(-5/12+-7/12)+7/18
=1+-1+7/18
=7/18
1) Tính
a) 9/12 - 5/12 ; 9/12 - 1/3 ; 7 - 3/2 ; 9/4 - 2
b) 2/7 + 5/7 ; 1/3 + 5/12 ; 2 + 2/5 ; 6/9 + 3
c) 2/3 x 4/7 ; 3/11 x 2 ; 4 x 2/7
d) 8/21 : 4/7 ; 8/7 : 4 ; 5 : 2/3
AI LÀM NHANH VÀ ĐÚNG NHẤT THÌ MÌNH TICK CHO!!!!
a] 4/12 ; 5/12 ; 11/2 ; 1/4
b] 1 ; 9/12; 12/5 ; 11/3
c] 8/21; 6/11;8/7
d] 2/3 ;2/7 15/2
a]1/3 5/12 11/2 1/4
b]1 3/4 12/5 33/9
c]8/21 6/11 8/7
d]2/3 2/7 15/2
a) 1/3 ; 5/12 ; 11/2 ; 1/14
b) 1 ; 9/12 ; 12/5 ; 11/3
c) 8/21 ; 6/11 ; 8/7
d) 2/3 ; 2/7 ; 15/2
Câu 1: Tính nhanh
a, 32 - ( 17 - 48 ) + 28
b, (-145 - 47 ) + 55 - 33
c, ( 2 . 14 ) + ( - 7 ) - ( - 5 ) - 12
d, 31 . 199
Câu 2: Tìm x
a, ( - 3 ) + x = 5 - ( - 7)
b, x - 2 = 2x -7
c, | 12 - x | = 0
d, | 5 + x | = 4
e, 15 - ( 7 - x ) + 3 x = ( - 15 ) + 18
f, 5 - x = 12 + ( - 7 )
\(-3+x=5-\left(-7\right)\)
\(\Leftrightarrow-3+x=5+7\)
\(\Leftrightarrow-3+x=12\)
\(\Leftrightarrow x=12+3\)
\(\Leftrightarrow x=15\)
Vậy x= 15
\(x-2=2x-7\)
\(\Leftrightarrow x-2+7=2x\)
\(\Leftrightarrow x-\left(2-7\right)=2x\)
\(\Leftrightarrow2-7=x-2x\)
\(\Leftrightarrow-5=-x\)
\(\Leftrightarrow x=5\)
Vậy x= 5
\(\left|12-x\right|=0\)
\(\Leftrightarrow12-x=0\)
\(\Leftrightarrow x=12-0\)
\(\Leftrightarrow x=12\)