kiet
Giới thiệu về bản thân
1. is doing/ does
2. use/ am not using
Chiều rộng: 36 x \(\dfrac{2}{3}\)= 24
Chu vi: (36 + 24) x 2 = 120 (m)
Diện tích: 36 x 24 = 864 (\(^{m^2}\))
ĐS:,.,.,.,.,.,.
y x 2,5 = \(\dfrac{40}{5}:\dfrac{20}{5}\)
y x 2,5 = 2
y = 2 : 2,5
y = 0,8
\(\dfrac{3}{2}m^2\) = 1500 \(cm^2\)
x = 7/3 - 8/9
x = 21/9 - 8/9
x = 13/9
a, X = 8 + 24/8
X = 11
b, X x 17/3 = 76/18 - 4/9
X x 17/3 = 34/9
X = 34/9 : 17/3
X = 2/3
Đặt A = \(\dfrac{3}{6\cdot8}+\dfrac{3}{8\cdot10}+...+\dfrac{3}{158\cdot160}\)
A = \(\dfrac{3}{2}\cdot\left(\dfrac{2}{6\cdot8}+\dfrac{2}{8\cdot10}+...+\dfrac{2}{158\cdot160}\right)\)
A = \(\dfrac{3}{2}\cdot\left(\dfrac{1}{6}-\dfrac{1}{8}+\dfrac{1}{8}-\dfrac{1}{10}+...+\dfrac{1}{158}-\dfrac{1}{160}\right)\)
A = \(\dfrac{3}{2}\cdot\left(\dfrac{1}{6}-\dfrac{1}{160}\right)\)
A = \(\dfrac{3}{2}\cdot\dfrac{77}{480}\)
A = \(\dfrac{77}{320}\)
Vậy: A = \(\dfrac{77}{320}\)
Khối gỗ đó nặng:
(2,4 x 2,4 x 2,4) x 0,5 = 6,912 (kg)
ĐS:.........