Thực hiện phép tính-tính nhanh giá trị biểu thức
A=19\(\dfrac{1}{4}\) + \(\dfrac{1}{2}\)x 2\(\dfrac{1}{3}\)+5,75 - \(\dfrac{1}{6}\)+74
B=[(\(\dfrac{1}{3}+\dfrac{1}{4}\))] x \(\dfrac{12}{19}+\dfrac{12}{19}\)] : \(\dfrac{4}{5}-\dfrac{1}{4}+2012\)
C=\(\dfrac{232323}{353535}:\dfrac{76x47-28}{76x46+48}\)
Bài 2: (đề 2) Tìm y
a) \(2\dfrac{2}{5}-y:2\dfrac{3}{4}=1\dfrac{1}{2}\) b) \(1\dfrac{1}{4}+2\dfrac{1}{5}\) x \(y=2\dfrac{3}{5}\)
c) \(2\dfrac{4}{5}-2\dfrac{1}{4}:y=\dfrac{3}{4}\) c) \(x:3\dfrac{1}{3}=2\dfrac{2}{5}+\dfrac{7}{10}\)
Tính:
a) (6 : \(\dfrac{3}{5}\) \(1\dfrac{1}{6}\) x \(\dfrac{6}{7}\) ) : ( \(4\dfrac{1}{5}\) x \(\dfrac{10}{11}\) + \(5\dfrac{2}{11}\) )
b) (\(1-\dfrac{1}{2}\)) x (\(1-\dfrac{1}{3}\)) x (\(1-\dfrac{1}{4}\)) x ..... x (\(1-\dfrac{1}{2003}\)) x (\(1-\dfrac{1}{2007}\))
Bài 1: tính
a) 3\(\dfrac{1}{2}\) + 4\(\dfrac{5}{7}\) - 5\(\dfrac{5}{14}\) b) 4\(\dfrac{1}{2}\) + \(\dfrac{1}{2}\) : \(5\dfrac{1}{2}\)
bài 2: tìm X
a) X x \(3\dfrac{1}{3}\) = \(3\dfrac{1}{3}\) : \(4\dfrac{1}{4}\) b) \(5\dfrac{2}{3}\) : X = \(3\dfrac{2}{3}\) - \(2\dfrac{1}{2}\)
các giáo viên olm giúp e vs, e cần gấp lắm!
A = \(\dfrac{1}{1+2}+\dfrac{1}{1+2+3}+\dfrac{1}{1+2+3+4}+...+\dfrac{1}{1+2+3+...+10}\)
Bài 1: (đề 2) Tính
a) \(2\dfrac{3}{8}:3\dfrac{3}{4}x2\dfrac{2}{3}\)=............
b) \(1\dfrac{1}{2}:\dfrac{7}{3}:2\dfrac{5}{6}\)=............
c) \(4\dfrac{2}{3}-1\dfrac{3}{4}:2\dfrac{2}{5}\)=............
a) \(\dfrac{1}{2}x\dfrac{1}{3}+y=\dfrac{3}{4}\) b)\(\dfrac{1}{2}x\dfrac{1}{5}+y=\dfrac{3}{10}\)
Bài 7: Tính
a) \(4\dfrac{2}{5}x8\dfrac{3}{4}-2\dfrac{3}{4}=...............................\)
b) \(2\dfrac{2}{3}+1\dfrac{2}{5}-\dfrac{2}{15}\)=..............................................
c) \(3\dfrac{1}{3}-2\dfrac{2}{3}+1\dfrac{5}{6}=...............................\)
Bài 7: (Đề 2) Tính nhanh
\(1\dfrac{1}{2}x1\dfrac{1}{3}x1\dfrac{1}{4}x...x1\dfrac{1}{999}\)