a ) 5/8 + x = 4/5
=> x = 4/5 - 5/8
=> x = 7/40
b) x - 3/4 : 5/6 = 2/3
=> x -3/4 = 2/3 x 5/6 = 5/9
=> x= 5/6+3/4
=> x= 19/12
a)\(\frac{5}{8}+x=\frac{4}{5}\)
\(\frac{25}{40}+x=\frac{32}{40}\)
\(x=\frac{32}{40}-\frac{25}{40}\)
\(x=\frac{7}{40}\)
5/8+x=4/5 x-3/4:5/6=2/3
x=5/8-4/5 x-3/4 =2/3x5/6
x=1/3 x -3/4 =5/9
x =5/9+3/4
x =9/3