Tính :
2 × 2 × 5 = ... = ....
30 : 3 : 2 = .... = ....
4 × 7 − 6 = .... = ....
5 × 5 + 15 = .... = ....
3 × 7 − 12 = .... = ....
4 : 4 + 25 = .... = ....
A -17/30 + 11/15 - 7/12
1/2+3/4-(3/4-4/5)
-7/25×11/13+ -7/25×2/13-18/25
(-3,2)+ -15/64+(0,8-2 4/15)÷3 2/3
-5/9+5/9÷(1 2/3- 2 1/12)
-5/7×2/11+ -5/7×9/11+ 1 5/7
(3/8+ -3/4+7/12)÷5/6+1/2
50%×1 1/3×10×7/35×0,75
Mn giúp mk với
\(\dfrac{1}{2}+\dfrac{3}{4}-\left(\dfrac{3}{4}-\dfrac{4}{5}\right)\)
=\(\dfrac{1}{2}+\dfrac{3}{4}-\dfrac{3}{4}+\dfrac{4}{5}\)
=\(\left(\dfrac{1}{2}+\dfrac{4}{5}\right)+\left(\dfrac{3}{4}-\dfrac{3}{4}\right)\)
=\(\left(\dfrac{5}{10}+\dfrac{8}{10}\right)+0\)
=\(\dfrac{13}{10}\)
\(-\dfrac{7}{25}.\dfrac{11}{13}+\left(-\dfrac{7}{25}\right).\dfrac{2}{13}-\dfrac{18}{25}\)
=\(-\dfrac{7}{25}.\cdot\left(\dfrac{11}{13}+\dfrac{2}{13}\right)-\dfrac{18}{25}\)
=\(-\dfrac{7}{25}.1-\dfrac{18}{25}\)
=\(-\dfrac{7}{25}-\dfrac{18}{25}\)
=\(-\dfrac{25}{25}\) = \(-1\)
(-3,2) +\(\dfrac{15}{64}+\left(0.8-2\dfrac{4}{15}\right):3\dfrac{2}{3}\)
=\(-\dfrac{16}{5}+\dfrac{15}{64}+(\dfrac{4}{5}-\dfrac{34}{15}):\dfrac{11}{3}\)
=\(-\dfrac{16}{5}+\dfrac{15}{64}+(-\dfrac{22}{5}):\dfrac{11}{3}\)
=\(-\dfrac{16}{5}+\dfrac{15}{64}+\dfrac{-2}{5}\)
=(\(-\dfrac{16}{5}+\dfrac{-2}{5}\)) +\(\dfrac{15}{64}\)
=\(-\dfrac{18}{5}+\dfrac{15}{64}\)
\(-\dfrac{1152}{320}+\dfrac{75}{320}\)
\(-\dfrac{1077}{320}\)
tính
a,[-5/8+(-3/4)]+15/6 b, 1/2-(3/4+-5/6)-7/12 c, 17/2-(-3/7+5/3) d,-3-2/3+[-10/9-25/3)-5/6
a: =-15/24-18/24+60/24
=27/24=9/8
b: =6/12-9/12-10/12-7/12=-20/12=-5/3
c: =17/2+3/7-5/3=305/42
c: =-3-2/3-10/9-25/3-5/6
=-10-19/9-5/6
=-180/18-38/18-15/18=-233/18
tính
a,[-5/8+(-3/4)]+15/6 b, 1/2-(3/4+-5/6)-7/12 c, 17/2-(-3/7+5/3) d,-3-2/3+[-10/9-25/3)-5/6
Tính nhanh:A=1*5*6+2*10*12+3*15*18+4*20*24+5*25*30/1*3*5+2*6*10+3*9*15+4*12*20+5*15*25
ta có : (ghi lại đề)
=6+12+18+24+30/3+6+9+12+15
=2*(3/3+6/6+9/9+12/12+15/15)
=2*(1+1+1+1+1)
=2*5=10
chúc main học tốt nhé
Bài 1: Tính:
A= ((2^12 . 3^5 - 4^6 . 9^3 ) / 9( 2^2 . 3 )^6 + (8^4 . 3^5))) - ((5^10 . 7^3 - 25^2 . 49^2) / (( 125 . 7 )^3 + 5^9 . 14^3))
B= (2^9 . 27^3 + 15 . 4^9 . 9^4) / (6^9 . 2^0 + 12^10)
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
4 [-2(8:4)+15(-3)-(-12)
3(25:5-14:2)-5(6:2)
[-15:(-3)]-3[2(5-9):3]
-16:(-4)[7-2(15:3)]
-7[8-3(14:7)-12:(-4)]-3(-2)
2[3-9:(-3)+2(5-7)]-18:(-9)
-16:(-8)+5[3-15:5+2] (-3+4)
4[-2(8:4)+15:(-3)-(-12)
3(25:5-14:2)-5(6:2)
[-15:(-3)]-3[2(5-9):3)]
-16:(-4)[7-2(15:3)]
-7[8-3(14:7)-12:(-4)]-3(-2)
2[3-9:(-3)+2(5-7)]-18:(-9)
-16:(-8)+5[3-15:5+2] (-3+4)
6 tính
0,5+1/3+0,4+5/7+1/8-4/35
8/9-1/12-1/56-1/42-1/30-1/20-1/12-1/6-1/2
7, tính
-4/7: (3/5x4/7)
1/4-2/3-11/18
6/7+1/7:5-8/15
(1/25-1/10):3/5+2/5
8 tính
a, -3,2: (1+2/3)
b, 1,4x15/49-(4/5+2/3:2/2/5
c, -4x-3/11x5/8.(-1/2/9)x0,6
d, (2-5/7):(11/14 - 1)
Các bài toán này bn bấm máy thì sẽ ra nha.
Bài 7 có quy tắc tính trong ngoặc trước, ngoài ngoặc sau.
7b bn nhóm 2/3 +1/18 lại vào một chỗ và để cho chúng dấu ngoặc
tíc mình nha