Tính nhẩm
57 + 17 + 3 = ...
1:tính nhanh
A=-3^17[2^3+3^17]
B=3^17+-5^13+-18^35+14^17+17^-35
Tính bằng cách hợp lý:
5/3 x 3/17 + 3/17 x 1/3 - 3/17 x 2
Chi tiết nha!
\(\dfrac{5}{3}\times\dfrac{3}{17}+\dfrac{3}{17}\times\dfrac{1}{3}-\dfrac{3}{17}\times2\)
\(=\dfrac{3}{17}\times\left(\dfrac{5}{3}+\dfrac{1}{3}+2\right)=\dfrac{3}{17}\times4=\dfrac{12}{17}\)
Thực hiện phép tính -3/17+(2/3+3/17)
-3/17+(2/3+3/17)
=-3/17+2/3+3/17
=(-3/17+3/17)+2/3
=0+2/3
=2/3
Tính: P=(1-1/17).(1-2/17).(1-3/17)....(1 - 17/17)
P= 0.(1-2/17).(1-3/17) .............(1/17)=0
nhớ**** nha
tính A= \(\sqrt[3]{3-\sqrt{17}}+\sqrt[3]{3-\sqrt{17}}\)
Tính
\(\sqrt{17-3\sqrt{32}}+\sqrt{17+3\sqrt{32}}\)
\(\sqrt{17-3\sqrt{32}}+\sqrt{17+3\sqrt{32}}\)
\(=\sqrt{17+12\sqrt{2}}+\sqrt{17-12\sqrt{2}}\)
\(=\sqrt{9+2.3.\sqrt{8}+8}+\sqrt{9-2.3.\sqrt{8}+8}\)
\(=\sqrt{\left(3+\sqrt{8}\right)^2}+\sqrt{\left(3-\sqrt{8}\right)^2}=\left|3+\sqrt{8}\right|+\left|3-\sqrt{8}\right|\)
\(=3+\sqrt{8}+3-\sqrt{8}\) (do \(3>\sqrt{8}\))
\(=6\)
Đặt tính rồi tính :
17 x 4 20 x 6 17 : 4 96 : 3
Thực hiện phép tính (Tính hợp lý): D=( 2\(\dfrac{2}{15}\).\(\dfrac{9}{17}\).\(\dfrac{3}{32}\)): (\(\dfrac{-3}{17}\))
Ta có: \(D=\left(2\dfrac{2}{15}\cdot\dfrac{9}{17}\cdot\dfrac{3}{32}\right):\left(-\dfrac{3}{17}\right)\)
\(=\dfrac{32}{15}\cdot\dfrac{9}{17}\cdot\dfrac{3}{32}\cdot\dfrac{-17}{3}\)
\(=\dfrac{-9}{15}=-\dfrac{3}{5}\)
Thực hiện phép tính (tính hợp lí nếu có thể):
a) -3/17 - (2/3 - 3/17)
b) 3/4 - 7/11 + (18/11 - 3/4 + 1/7)
tính
-3/17 + ( 2/3 + 3/17 )
\(\frac{-3}{7}+\left(\frac{2}{3}+\frac{3}{17}\right)=\frac{-3}{17}+\frac{2}{3}+\frac{3}{17}\)
\(=\left(\frac{-3}{17}+\frac{3}{17}\right)+\frac{2}{3}\)
\(=0+\frac{2}{3}=\frac{2}{3}\)
-3/17 + (2/3+3/17)
= -3/17+2/3+3/17
=(-3/17 + 3/17)+2/3
= 0 + 2/3
= 2/3