Bài 1 : thực hiện phép tính :
1) 25% - \(1\dfrac{1}{2}\) + 0,5.\(\dfrac{12}{5}\)
2) (-3,2) . \(\dfrac{-15}{64}\) + (0,8-\(2\dfrac{4}{15}\)) : 3\(\dfrac{1}{2}\)
e) \(\left(15-6\dfrac{13}{18}\right)\):\(12\dfrac{1}{27}\)-\(2\dfrac{1}{8}\):\(1\dfrac{11}{40}\)
g) (-3,2).\(\dfrac{-15}{64}\)+\(\left(0,8-2\dfrac{4}{15}\right)\):\(3\dfrac{2}{3}\)
Đề bài là:Tính các giá trị biểu thức sau ạ
a: \(=\left(9-\dfrac{13}{18}\right):\dfrac{325}{27}-\dfrac{17}{8}:\dfrac{51}{40}\)
\(=\dfrac{149}{18}\cdot\dfrac{27}{325}-\dfrac{17}{8}\cdot\dfrac{40}{51}\)
\(=\dfrac{447}{650}-\dfrac{5}{3}=-\dfrac{1909}{1950}\)
b: \(=\dfrac{48}{64}+\left(\dfrac{4}{5}-2-\dfrac{4}{15}\right):\dfrac{11}{3}\)
\(=\dfrac{3}{4}+\dfrac{-22}{15}\cdot\dfrac{3}{11}=\dfrac{3}{4}-\dfrac{2}{5}=\dfrac{15-8}{20}=\dfrac{7}{20}\)
Các bạn cho mình hỏi: Thực hiện phép tính
(2\(\dfrac{1}{3}\) + 3\(\dfrac{1}{2}\)) : (- 4\(\dfrac{1}{6}\) + 3\(\dfrac{1}{7}\)) + 7,5
`(2 1/3 + 3 1/2): (-4 1/6 + 3 1/7) +7,5`
`=(7/3 +7/2) : (-25/6 + 22/7) + 15/2`
`=35/6 : (-43/42) + 15/2`
`=-245/43+15/2`
`=155/86`
Thực hiện phép tính:
\(\dfrac{4}{x+2}-\dfrac{3}{2-x}-\dfrac{5x+2}{x^2-4}\)
tính:
a) \(2\dfrac{3}{4}.\left(-0,4\right)-1\dfrac{3}{5}.2,75+\left(-1,2\right):\dfrac{4}{11}\)
b) \(1,4.\dfrac{15}{49}-\left(\dfrac{4}{5}+\dfrac{2}{3}\right):2\dfrac{1}{5}\)
c) \(\left(-3,2\right).\dfrac{15}{64}+\left(0,8-2\dfrac{4}{15}\right):3\dfrac{2}{3}\)
d) \(0,02.\dfrac{-25}{2}+\dfrac{3}{8}+\left(-2\dfrac{9}{20}\right).\dfrac{2}{7}\)
e) \(34\%:\dfrac{51}{16}-3\dfrac{7}{9}.6,5-\left(0,4\right)^2\)
Cái này bn lầy máy tính ra tính tí là xong thôi
a) \(2\dfrac{3}{4}.\left(-0,4\right)-1\dfrac{3}{5}.2,75+\left(-1,2\right):\dfrac{4}{11}\)
= \(2,75.\left(-0,4\right)-\left(1,6\right).\left(2,75\right)+\left(-1,2\right).\dfrac{11}{4}\)
= \(2,75.\left(-0,4\right)-\left(1,6\right).\left(2,75\right)+\left(-1,2\right).\left(2,75\right)\)
= \(2,75.\left\{\left(-0,4\right)-\left(1,6\right)+\left(-1,2\right)\right\}\)
= \(2,75.\left(-3,2\right)\)
= \(-8,8\)
b) \(1,4.\dfrac{15}{49}-\left(\dfrac{4}{5}+\dfrac{2}{3}\right):2\dfrac{1}{5}\)
= \(\dfrac{7}{5}.\dfrac{15}{49}-\left(\dfrac{4}{5}+\dfrac{2}{3}\right):\dfrac{11}{5}\)
= \(\dfrac{7}{5}.\dfrac{15}{49}-\dfrac{22}{15}.\dfrac{5}{11}\)
= \(\dfrac{3}{7}-\dfrac{2}{3}\)
= \(-\dfrac{5}{21}\)
c) \(\left(-3,2\right).\dfrac{15}{64}+\left(0,8-2\dfrac{4}{15}\right):3\dfrac{2}{3}\)
= \(-\dfrac{16}{5}.\dfrac{15}{64}+\left(\dfrac{4}{5}-2\dfrac{4}{15}\right):\dfrac{11}{3}\)
= \(-\dfrac{16}{5}.\dfrac{15}{64}+\left(-\dfrac{22}{15}\right).\dfrac{3}{11}\)
= \(\left(-\dfrac{3}{4}\right)+\left(-\dfrac{2}{5}\right)\)
= \(-\dfrac{23}{20}\)
d) \(0,02.\dfrac{-25}{2}+\dfrac{3}{8}+\left(-2\dfrac{9}{20}\right).\dfrac{2}{7}\)
= \(\dfrac{1}{50}.\dfrac{-25}{2}+\dfrac{3}{8}+\left(-\dfrac{49}{20}\right).\dfrac{2}{7}\)
=\(\left(-\dfrac{1}{4}\right)+\dfrac{3}{8}+\left(-\dfrac{7}{10}\right)\)
= \(\dfrac{1}{8}+\left(-\dfrac{7}{10}=\right)\)
= \(-\dfrac{23}{40}\)
e) \(34\%:\dfrac{51}{16}-3\dfrac{7}{9}.6,5-\left(0,4\right)^2\)
= \(\dfrac{17}{50}.\dfrac{16}{51}-\dfrac{34}{9}.\dfrac{13}{2}-\dfrac{4}{25}\)
= \(\dfrac{8}{75}-\dfrac{221}{9}-\dfrac{4}{15}\)
= \(-\dfrac{5501}{225}\)
Thực hiện phép tính
a, \(\dfrac{3}{x+3}-\dfrac{x-6}{x^2+3}\)
b, \(\dfrac{2x^2-x}{x-1}+\dfrac{x+1}{1-x}+\dfrac{2-x^2}{x-1}\)
\(\dfrac{2x^2-x}{x-1}+\dfrac{x+1}{1-x}+\dfrac{2-x^2}{x-1}.\left(x\ne1\right).\)
\(\dfrac{2x^2-x-x-1+2-x^2}{x-1}=\dfrac{x^2-2x+1}{x-1}=\dfrac{\left(x-1\right)^2}{x-1}=x-1.\)
(-3,2) . \(\dfrac{15}{64}\) - (0,8 - \(2\dfrac{4}{15}\)) : \(3\dfrac{2}{3}\)
\(\left(-3,2\right).\dfrac{15}{64}-\left(0,8-2\dfrac{4}{15}\right):3\dfrac{2}{3}\\ =-\dfrac{16}{5}.\dfrac{15}{64}-\left(\dfrac{4}{5}-\dfrac{34}{15}\right):\dfrac{11}{3}\\ =-\dfrac{3}{4}-\left(-\dfrac{22}{15}\right).\dfrac{3}{11}\\ =-\dfrac{3}{4}-\left(-\dfrac{2}{5}\right)=-\dfrac{3}{4}+\dfrac{2}{5}=-\dfrac{7}{20}\)
(-3,2) . \(\dfrac{-15}{64}\) + (0,8 - 2\(\dfrac{4}{15}\) ) : 3\(\dfrac{2}{3}\)
\(\left(-3,2\right).\dfrac{-15}{64}+\left(0,8-2\dfrac{4}{15}\right):3\dfrac{2}{3}\)
\(=\left(\dfrac{-16}{5}\right).\dfrac{-15}{64}+\left(\dfrac{4}{5}-\dfrac{34}{15}\right):\dfrac{11}{3}\)
\(=\left(\dfrac{-16}{5}\right).\dfrac{-15}{64}+\left(\dfrac{-22}{15}\right).\dfrac{3}{11}\)
\(=\dfrac{3}{4}+\left(\dfrac{-2}{5}\right)\)
\(=\dfrac{7}{20}\)
Giúp mình với
1. Thực hiện phép tính (Tính nhanh nếu có thể):
a) \(\left(\dfrac{3}{8}+\dfrac{-4}{3}+\dfrac{7}{12}\right)\div\dfrac{5}{6}+\dfrac{1}{2}\)
b) \(0,5\times11\dfrac{1}{3}\times75\%\div\dfrac{2}{5}+\dfrac{3}{5}\)
c) \(-5^2-4\dfrac{1}{2}\left(10,6-1\dfrac{3}{5}\right)+75\%\)
d) \(\left(-3,2\right)\times\dfrac{-15}{64}+\left(0,8-2\dfrac{4}{15}\right)\div3\dfrac{2}{3}\)
e) \(\dfrac{-3}{5}\times\dfrac{2}{7}+\dfrac{-3}{5}\times\dfrac{5}{7}+2\dfrac{3}{5}\)
e) \(\dfrac{-3}{5}.\dfrac{2}{7}+\dfrac{-3}{5}.\dfrac{5}{7}+2\dfrac{3}{5}\)
= \(\dfrac{-3}{5}.\left(\dfrac{2}{7}+\dfrac{5}{7}\right)+\dfrac{13}{5}\)
= \(\dfrac{-3}{5}.1+\dfrac{13}{5}\)
= \(\dfrac{-3}{5}+\dfrac{13}{5}\)
= 2
Thực hiện phép tính
a) (x\(^2\)-3x+4)(-3x+1)
b)\(\dfrac{1}{x}\)+\(\dfrac{1}{x+5}\)+\(\dfrac{x-5}{x^2+5x}\)
Mọi người giúp mình nhanh nha mình cần gấp
b: \(=\dfrac{x+5+x+x-5}{x\left(x+5\right)}=\dfrac{3x}{x\left(x+5\right)}=\dfrac{3}{x+5}\)
\(a,=-3x^3+x^2+9x^2-3x-12x+4=-3x^3+10x^2-15x+4\\ b,=\dfrac{x+5+x+x-5}{x\left(x+5\right)}=\dfrac{3x}{x\left(x+5\right)}=\dfrac{3}{x+5}\)