Question

Giúp mình nha

Answer 1

Bài 2:

a: \(8m4dm=840cm\)

\(\dfrac{2}{5}m^2=40dm^2\)

\(12m^26dm^2=1206dm^2\)

2h16'=136'

b: \(x-\dfrac{5}{6}=\dfrac{2}{3}\) nên x=2/3+5/6=3/2

\(x\cdot\dfrac{2}{5}=\dfrac{6}{7}\)

nên \(x=\dfrac{6}{7}:\dfrac{2}{5}=\dfrac{30}{14}=\dfrac{15}{7}\)

Answer 2

bài 2)

a) 8m = 800cm

4dm = 40cm

800 + 40 = 840cm

b) 

\(\dfrac{2}{5}\times100=40dm^2\)

c)

12m² = 1200dm²

1200 + 6 = 1206 dm²

d)

2 giờ = 2 x 6 = 120 phút

120 + 16 = 136 phút

 

bài 3)

\(x-\dfrac{5}{6}=\dfrac{2}{3}\)

\(x=\dfrac{2}{3}+\dfrac{5}{6}\)

\(x=\dfrac{3}{2}\)

 

\(\dfrac{2}{5}\times x=\dfrac{6}{7}\)

\(x=\dfrac{6}{7}:\dfrac{2}{5}\)

\(x=\dfrac{6}{7}\times\dfrac{5}{2}\)

\(x=\dfrac{15}{7}\)

Answer 3

Bài 2:

8m 4dm = 840cm               12m² 6dm² = 1206dm²

\(\dfrac{2}{5}m^2=40dm^2\)                    2 giờ 16 phút = 136 phút

\(x-\dfrac{5}{6}=\dfrac{2}{3}\)                          \(\dfrac{2}{5}\times x=\dfrac{6}{7}\)

 

\(x=\dfrac{2}{3}+\dfrac{5}{6}\)                          \(x=\dfrac{6}{7}:\dfrac{2}{5}\)

\(x=\dfrac{3}{2}\)                                  \(x=\dfrac{15}{7}\)