tinh hop li A= 15\(\frac{1}{4}\): \(\frac{-5}{7}\)- 25\(\frac{1}{4}\): \(\frac{-5}{7}\)
B= -(251.3+281)+3.251-(1-281)
Bài 1 : Tính giá trị của các biểu thức sau đã bỏ dấu ngoặc :
A= (3,1 - 2,5) - (-2,5 + 3,1)
B= (5,3 - 2,8) - (4 + 5,3)
C= -(251.3 + 281) + 3.251 - (1-281)
D= -\(\left(\frac{3}{5}+\frac{3}{4}\right)-\left(-\frac{3}{4}+\frac{2}{5}\right)\)
A= (3,1 - 2,5) - (-2,5 + 3,1)
=3.1-2.5+2.5-3.1
=0
B= (5,3 - 2,8) - (4 + 5,3)
=5.3 - 2.8-4-5.3
= -6.8
C= -(251.3 + 281) + 3.251 - (1-281)
=-251.3-281+3.251-1+281
=-1
D= -(3/5+3/4)−(−3/4+2/5)
= -3/5-3/4+3/4-2/5
= -5/5
=-1
\(A=\left(3,1-2,5\right)-\left(-2,5+3,1\right)=3,1-2,5+2,5-3,1=0\)
\(B=\left(5,3-2,8\right)-\left(4+5,3\right)=5,3-2,8-4-5,3=-6,8\)
\(C=-\left(215\cdot3+281\right)+3\cdot215-\left(1-281\right)=-215\cdot3-281+3\cdot215-1+281=1\)
\(D=-\left(\frac{3}{5}+\frac{3}{4}\right)-\left(-\frac{3}{4}+\frac{2}{5}\right)=-\frac{3}{5}-\frac{3}{4}+\frac{3}{4}-\frac{2}{5}=-1\)
Bài 1 : Tính giá trị của các biểu thức sau đã bỏ dấu ngoặc :
A= (3,1 - 2,5) - (- 2,5 + 3,1) = 3,1 - 2,5 + 2,5 - 3,1 = 0
B= (5,3 - 2,8) - (4 + 5,3) = 5,3 - 2,8 - 4 - 5,3 = - 6,8
C= - (251.3 + 281) + 3.251 - (1 - 281) = - 753 - 281 + 753 + 280 = - 1
D= - (35 + 34) − ( − 34 + 25) = - 35 - 34 + 34 - 25 = - 60
tính giá trị của các biểu thức sau khi đã bỏ dấu ngoặc
A=\(\left(3,1-2,5\right)-\left(-2,5+3,1\right)\)
B=\(\left(5,3-2,8\right)-\left(4+5,3\right)\)
C=\(-\left(251.3+281\right)+3.251-\left(1-281\right)\)
D=\(-\left(\frac{3}{5}+\frac{3}{4}\right)-\left(-\frac{3}{4}+\frac{2}{5}\right)\)
A = \(\left(3,1-2,5\right)-\left(-2,5+3,1\right)\)
\(=3,1-2,5+2,5-3,1=6,2\)
B = \(\left(5,3-2,8\right)-\left(4+5,3\right)\)
\(=5,3-2,8-4-5,3=-6,8\)
C = \(-\left(251.3+281\right)+3.251-\left(1-281\right)\)
\(=-251.3-281+3.251-1+281=-1\)
D = \(-\left(\frac{3}{5}+\frac{3}{4}\right)-\left(-\frac{3}{4}+\frac{2}{5}\right)\)
\(=-\frac{3}{5}-\frac{3}{4}+\frac{3}{4}-\frac{2}{5}=-1\)
(Nhớ k cho mình với nhá!)
-(251.3+281)+3.251-(1-281)
-(251.3+281)+3.251-(1-281)
=-251.3-281+3.251-1+281
=-1
Dễ ợt thế này mà
-(251.3+281)+3.251-(1-281)
= 251.3-281+3.251-1+281
= 251.3.(281+281)-1
= 251.3.526-1
= 753.526-1
= 396078-1
= 296077
~~~Learn Well Ánh Duyên Hoàng Thị~~~
Thực hiện phép tính:(hợp lý nếu có thể)
a, \(5.\dfrac{5}{27}+\dfrac{7}{23}+0,5.\dfrac{5}{7}+\dfrac{16}{23}+\dfrac{1}{2}\)
b, \(25\dfrac{1}{6}:\dfrac{-4}{5}-45\dfrac{1}{6}:\dfrac{-4}{5}\)
c, \(25.\left(\dfrac{-1}{5}\right)^3+\dfrac{1}{5}-2.\left(\dfrac{-1}{2}\right)^2-\dfrac{1}{2}\)
d, \(-\left(251.3+281\right)+3.251-\left(1-281\right)\)
e, \(\left(0,75-\dfrac{1}{4}\right):\left(-5\right)+\dfrac{1}{15}-\left(-\dfrac{1}{5}\right):\left(-3\right)\)
f, \(\sqrt{\dfrac{4}{81}}:\sqrt{\dfrac{25}{81}}-1\dfrac{2}{5}\)
Tinh bang cach hop li
c)\(\frac{-5}{7}+\frac{3}{4}+\frac{-1}{5}+\) \(\frac{-2}{7}+\frac{1}{4}\)
bằng-1/5
\(\frac{-5}{7}+\frac{3}{4}+\frac{-1}{5}+\frac{-2}{7}+\frac{1}{4}\)
\(=\left(\frac{-5}{7}+\frac{-2}{7}\right)+\left(\frac{3}{4}+\frac{1}{4}\right)+\frac{-1}{5}\)
\(=-1+1+\frac{-1}{5}\)
\(=-\frac{1}{5}\)
Tinh bang cach hop li
c) \(\frac{-5}{7}+\frac{3}{4}+\frac{-1}{5}\) \(+\frac{-2}{7}+\frac{1}{4}\)
=(-5/7-2/7)+(3/4+1/4)-1/5=-1+1-1/5=-1/5
(-5/7+-2/7)+(3/4+1/4)+-1/5
-1+1+-1/5
-1/5
c, \(\frac{-5}{7}+\frac{3}{4}+\frac{-1}{5}+\frac{-2}{7}+\frac{1}{4}\)
\(=\left(-\frac{5}{7}-\frac{2}{7}\right)+\left(\frac{3}{4}+\frac{1}{4}\right)-\frac{1}{5}\)
\(=-1+1-\frac{1}{5}=-\frac{1}{5}\)
Thực hiện phép tính :
B=(-251.3 + 281) + 3.251 - (1-281) .
B= (-251.3+281)+3.251 -(1-281)
B=(-753+281)+753-(-280)
B=-472+753+280
B= 281+280
B= 561
\(-\left(251.3+281\right)+3.251-\left(1-281\right)\))
Ta có :
-251.3-281+3.251-1+281
=-281-1+281
=-1
:)) đây nhé bạn
\(-\left(251.3+281\right)+3.251-\left(1-281\right)\)
\(=-251.3-281+3.251-1+281\)
\(=3.\left(251-251\right)+\left(-281+281\right)-1\)
\(=3.0+0-1\)
\(=-1\)
a, \(\frac{\frac{7}{12}+\frac{5}{6}-1}{5-\frac{3}{4}+\frac{1}{3}}\)