Question

find a no whose double is 45 greater than its half

Answer 1

let the number be x.
2x=45+x/2
2x=(90+x)/2
4x=90+x
3x=90
x=90/3
x=30.

Answer 2

let the no. be 2x
thus, it's double = 4x
and its half will be x
a/q,
4x=45+x
3x=45
x=15

thus, the no. is 2x=2×15=30