bài 1: Tìm \(x\)
a, \((\dfrac{25}{6}-x)\) x 2 \(=2\dfrac{1}{2}:\dfrac{5}{3}\) b, \((x\)x\(\dfrac{1}{2})\) \(+\dfrac{2}{7}=\dfrac{4}{7}+2\dfrac{3}{4}\)
bài 2: Tính
a, \(4\dfrac{3}{5}-\dfrac{7}{5}:2\dfrac{1}{3}\) b, \(2\dfrac{7}{12}+3\dfrac{1}{4}\)x\(\dfrac{5}{26}\)
bài 3:Một mảnh đất hình chữ nhật có chiều dài \(9\dfrac{2}{3}\)m,chiều rộng bằng \(\dfrac{1}{2}\) chiều dài.Tính chu vi và diện tích mảnh đất hình chữ nhật đó.
bài 1 :
a, ( 25/6 -x) x 2 = 2\(\dfrac{1}{2}\) : \(\dfrac{5}{3}\)
( 25/6 -x ) x 2 = \(\dfrac{3}{2}\)
25/6 - x = 3/2 : 2
25/6 - x = 3/4
x = 25/6 - 3/4
x = 41/12
b, X x \(\dfrac{1}{2}\) + 2/7 = 4/7 + 2\(\dfrac{3}{4}\)
X x \(\dfrac{1}{2}\) + \(\dfrac{2}{7}\) = \(\dfrac{93}{28}\)
X x \(\dfrac{1}{2}\) = \(\dfrac{93}{28}\)- \(\dfrac{2}{7}\)
X x 1/2 = 85/28
X = 85/28 : 1/2
X = 85/14
bài 2
a, 4\(\dfrac{3}{5}\) - \(\dfrac{7}{5}\) : 2\(\dfrac{1}{3}\)
= \(\dfrac{23}{5}\) - \(\dfrac{7}{5}\) : \(\dfrac{7}{3}\)
= \(\dfrac{23}{5}\)- \(\dfrac{3}{5}\)
= 4
b , 2\(\dfrac{7}{12}\) + 3\(\dfrac{1}{4}\)x \(\dfrac{5}{26}\)
= \(\dfrac{31}{12}\) + \(\dfrac{13}{4}\) x \(\dfrac{5}{26}\)
= \(\dfrac{31}{12}\) + \(\dfrac{5}{8}\)
= \(\dfrac{77}{24}\)