Question

if 21y5 is divisible by 9, find the value of y.

Answer 1

Equation-
2+1+y+5=9
8+y=9
y=9-8
y=1
This is the least value of y

Answer 2

Equation-
2+1+y+5=9
8+y=9
y=9-8
y=1

proof:- 2115/9 = 9