Question

các bạn giải chi tiết hộ mình nhé

Tìm x, biết 

a)x : 9/7 = -3,5

b)0,4 x X -1/5 x =3/4

Answer 1

a) \(x=-\dfrac{3}{5}\times\dfrac{9}{7}=-\dfrac{27}{35}\)

b) \(x\left(0,4-\dfrac{1}{5}\right)=\dfrac{3}{4}\)

\(x=\dfrac{3}{4}:\dfrac{1}{5}=\dfrac{15}{4}\)

Answer 2

a, \(x=-3,5.\dfrac{9}{7}=-\dfrac{9}{2}\)

b, \(\dfrac{2}{5}x-\dfrac{1}{5}x=\dfrac{3}{4}\Leftrightarrow\dfrac{1}{5}x=\dfrac{3}{4}\Leftrightarrow x=\dfrac{3}{4}:\dfrac{1}{5}=\dfrac{15}{4}\)

Answer 3

x=\(\dfrac{9}{7}x-3.5\)

x=\(\dfrac{-9}{5}\)

Answer 4

a, x : 9/7 = -3,5

x = -3,5 x 9/7

x = -9/2 = -4,5

b, 0,4 x X - 1/5X = 3/4

X x (0,4 - 1/5) = 3/4

X x 1/5 = 3/4

X = 3/4 : 1/5

X = 15/4 = 3,75