1.tính
a)\(\left(4-\dfrac{12}{5}\right).\dfrac{25}{8}-\dfrac{2}{5}:\dfrac{-4}{25}\)
b)\(\left(\dfrac{-5}{24}+\dfrac{3}{4}-\dfrac{7}{12}\right):\left(\dfrac{-5}{16}\right)\)
c)\(\dfrac{6}{7}+\dfrac{5}{4}:\left(-5\right)-\dfrac{-1}{28}.\left(-2\right)^2\)
ai giải đc mik sẽ tick
Thực hiện phép tính :
a, 4/5 ( 1/2 - 7/4 ) - 3/4 ( 1/3 - 8/12 ) + 15/4 : -5/8 - 6/5 : 1/10
b, [ -5/9 ] ( 1/5 - 11/10 ) : 3/2 - 3/4 ( 7/6 - 1/3 ) + 28/5 : -7/10
a) 7/-25+8/25 ; 4/5+4/-18 ; 7/21+9/-36
b) 12/20-2/5 ; 2/3-(-5/6) ; 6-3/20
c)2/21*(-7/3) ; 27/28*(-21) ; -15/7*(-14/25)
ai nhanh mk tk cho giup k nhe minh can gap
tính tổng
B= 7-7 mu 4 + 7 mu 4 -........+7 mu 301
A = 1 + 5 mũ 2 + 5 mu 4 + 5 mu 6 +.....+5 mu 200
tính
A= 1/7+1/7mu 2 + 1/7 mu 3+......+1/7mu 100
B=-4/5+4/5 mu 2 - 4/5 mu 3 + ....+4/5mu 200
tính A=25 mũ 8 + 25 mũ 4 + 25 mu 20 +......+25 mu 4 +1 / 25 mu 20 + 25 mu 28 + 25 mu 26 +.....= 25 mu 2 +1
Tìm x biết
a, 1/7.x = 9/8 - 0,125
b, x - 25% . x = 1/2
c, ( 50%x + 9/4 ) . -2/3 = 17/6
d,( 3x/7 + 1 ) : ( - 4)3 = -1/28
e, (4/3 - 25% - 5/12 ) - 2x = 1,6 : 3/5
Tính 1) 4/5 +13/18 2) 3/7 -11/8 3) -7/10 - -4/5 4) 3/20 -1/25 5) 2/3 - 5/6 6) 1/4 + -3/8 - 19/10 7) -9/10 - -7/18 8) 3/10 - 11/18 9) 3/5 -5/6 + -7/12 10) -4/9 - (-5 )/6 - 3/8
Tính các tổng sau:
1, S=1-2+3_4+..+25-26
2, S=1-3+5-7+...+49-51
3, S=-1+3-5+7-...-53+55
4, S=2-4+6-8+...+22-24
5, S=-2+4-6+8-...-26+28
6, S=2-5+8-11+...-29+32
7, S=-1+5-9-13-...-41-45
8, S=1-5+9-13+...++89-93
9, S=2-4+6-8+...+202-204
10, S=1-6=11-16+21-26+...+171-176
huhu giúp mình với ạ 2h chiều nay mình phải nộp r =(((
Bài toán 3 : Tìm x, biết.
a. 2(x – 5) – 3(x + 7) = 14 b. 5(x – 6) – 2(x + 3) = 12
c. 3(x – 4) – (8 – x) = 12 d. -7(3x – 5) + 2(7x – 14) = 28
e. 5(3 – 2x) + 5(x – 4) = 6 – 4x f. -5(2 – x) + 4(x – 3) = 10x – 15
g. 2(4x – 8) – 7(3 + x) = |-4|(3 – 2) h. 8(x – |-7|) – 6(x – 2) = |-8|.6 – 50
k. -7(5 – x) – 2(x – 10) = 15 l. 4(x – 1) – 3(x – 2) = -|-5|
m. -4(x + 1) + 89x – 3) = 24 n. 5(x – 30 – 2(x + 6) = 9
o. -3(x – 5) + 6(x + 2) = 9 p. 7(x – 9) – 5(6 – x) = – 6 + 11x
q. 10(x – 7) – 8(x + 5) = 6.(-5) + 24
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
