Question

when half a number is increased by 15, the result is 39. the sum of digits of the original number is​

Answer 1

Step-by-step explanation:

Let n = the original number.

Half of n is increased by 15 is expressed by (1/2)n + 15 = (n/2) + 15.

When half of some number n is increased by 15 and the result is 39, we can write the following equation and solve for n:

(n/2) + 15 = 39

Now, multiply both sides by 2 to clear the equation of fractions:

2[(n/2) + 15] = 2(39)

2(n/2) + 2(15) = 2(39)

(2/2)n + 30 = 78

(1)n + 30 = 78

n + 30 = 78

Now, subtract 30 from both sides of the equation:

n + 30 - 30 = 78 - 30

n + 0 = 48

n = 48

CHECK:

(n/2) + 15 = 39

(48/2) + 15 = 39

24 + 15 = 39

39 = 39

Therefore, n = 48 is indeed the original number.