Question

If a number is doubled and the result is increased by 5 we get 45 find the number

Answer 1

Let the number be 'x'.
Double the number=2x
Increased by 5=2x+5
2x+5=45
2x=45-5
2x=40
x=40/2
x=20

Answer 2

HEY MATE HERE IS YOUR ANSWER.....
$let \:no \: be \: y \\ let \: doubed \: no \: of \: first \: no \: be \: 2y \\ if \: we \: add \: 5 \: to \: it \: we \: get \: \\ 2y + 5 = 45 \\ 2y = 45 - 5 \\ 2y = 40 \\ y = \frac{40}{2} \\ y = 20$
HOPE IT HELPS YOU....