Question

Tìm y

a) 2/3  Nhân y =3/5

b) 2/5 :y = 7/10

c)  4/5 -y = 5/7

d) y : 2/5 +1 =7/2

Bài 2 điền dấu ( lớn, bế, bằng  )

a)  4m²5cm² ...............405 cm²

b) 670ha ............. 67km²2

c) 9dm²42cm² ......942cm²2

d) 120m²7dm² ..........1207 dam²

Answer 1

\(a,\frac{2}{3}.y=\frac{3}{5}\)

\(y=\frac{3}{5}:\frac{2}{3}\)

\(y=\frac{9}{10}\)

b, \(\frac{2}{5}:y=\frac{7}{10}\)

\(y=\frac{2}{5}:\frac{7}{10}\)\(y=\frac{4}{7}\)

\(c,\frac{4}{5}-y=\frac{5}{7}\)

\(y=\frac{4}{5}-\frac{5}{7}\)

\(y=\frac{3}{35}\)

\(d,y:\frac{2}{5}+1=\frac{7}{2}\)

\(y:\frac{2}{5}=\frac{5}{2}\)

\(y=\frac{5}{2}.\frac{2}{5}\)

\(y=1\)

Answer 2

 a/    2/3*y=3/5 =>y=3/5:2/3=>y=9/10                               b/    thôi giác làm để minh lbt