Question

tính nhanh

a) \(\dfrac{5}{7}x\dfrac{3}{2}+\dfrac{3}{2}x\dfrac{9}{7}\)

b)\(\dfrac{4}{5}+\dfrac{4}{5}x6+3x\dfrac{4}{5}\)

sos

Answer 1

\(=\left(\dfrac{5}{7}+\dfrac{9}{7}\right)\times\dfrac{3}{2}=2\times\dfrac{3}{2}=3\)

\(=\dfrac{4}{5}\times\left(6+1+3\right)=\dfrac{4}{5}\times10=\dfrac{40}{5}=8\)

Answer 2

a) 5/7 x 3/2 + 3/2 x 9/7 
= (5/7 + 9/7) x 3/2
= 2 x 3/2
= 6/2 = 3
b) 4/5 + 4/5 x 6 + 3 x 4/5
= 4/5 x 1 + 4/5 x 6 + 3 x 4/5
= 4/5 x (1 + 6 + 3)
= 4/5 x 10
= 40/5 = 8

Answer 3

=2 × 3/2

b. =4/5 × (6 + 1 + 3)

=40/5