Question

If the sum of Noor's age and Salma's age = 30, 3 years ago Noor's

Answer 1

Answer:

Noor's age is 12 & Salma's age is 18

Step-by-step explanation:

Noor's age: N

Salma's age: S

$N+S=30$             : given

$N - 3 = \frac{S}{2}$               : given

$N = \frac{S}{2}+3$               : isolate "N"

$\frac{S}{2}+3 + S = 30$        : substitute the value of N for N to find the value of "S"

$\frac{S}{2} + S = 27$             : subtract 3 from both sides

$\frac{S}{2}*2 + S*2 = 27*2$   ≡   $S + 2S = 54$       : multiply both sides by 2

$3S = 54$  : add like values

$\frac{3S}{3} = \frac{54}{3}$   : divide both sides by 3

S = 18

now insert that value into the initial equation:

$N + 18 = 30$

$N = 12$  : subtract 18 from both sides