Question

Tìm y, biết:

a. y+30% y = -1,3 c. ₃\(\dfrac{1}{3}\)y+ 16\(\dfrac{3}{4}\) = -13,25

b. y-25% y = \(\dfrac{1}{2}\)

PLEASE HELP ME

Answer 1

a. \(y+30\%y=-1,3\)

\(=>y.\left(1+30\%\right)=-1,3\)

\(=>y.\left(1+\dfrac{3}{10}\right)=-1,3\)

\(=>y.\dfrac{13}{10}=\dfrac{-13}{10}\)

\(=>y=-1\)

b.\(y-25\%y=\dfrac{1}{2}\)

\(=>y.\left(1-25\%\right)=\dfrac{1}{2}\)

\(=>y.\left(1-\dfrac{1}{4}\right)=\dfrac{1}{2}\)

\(=>y.\dfrac{3}{4}=\dfrac{1}{2}\)

\(=>y=\dfrac{1}{2}.\dfrac{4}{3}\)

\(=>y=\dfrac{2}{3}\)

c.\(3\dfrac{1}{3}y+16\dfrac{3}{4}=-13,25\)

\(=>\dfrac{10}{3}y+\dfrac{67}{4}=\dfrac{-53}{4}\)

\(=>\dfrac{10}{3}y=\dfrac{-53-67}{4}\)

\(=>\dfrac{10}{3}y=\dfrac{-120}{4}\)

\(=>\dfrac{10}{3}y=-30\)

\(=>y=-30.\dfrac{3}{10}\)

\(=>y=-9\)

tick cho mk nha

k hiểu chỗ nào thì hỏi mk