Question

a number is increased by 21 is equal to half of the number increased by 18.5 what is the number

Answer 1

x + 21 = (x + 18.5) × 2
x + 21 = 2x + 37
     -37           -37
_____________
x - 16 = 2x
-x          -x
-16 = x

-16 + 21 = 5
-16 + 18.5 = 2.5

The number is -16.