Question

find a number whose double is 45 greater than its half

Answer 1

let the number be x
double=2x

2x=45+x/2
4x=45+x
3x=45
x=15

Answer 2

Let the no. be x
2x=45+x/2
2x-x/2=45
3x/2=45
x=45*2/3
x=30