Answer:
Anita= 25 years old
Sumbo= 10 years old
Explanation:
Start by forming 2 equations that represent the given information.
Let Anu's and Sumbo's ages be A and S respectively.
A= S +15 -----(1)
A² +S²= 725 -----(2)
Now, solve for A and S by substitution.
Substitute (1) into (2):
(S +15)² +S²= 725
Expand:
S² +2(S)(15) +15² +S²= 725
2S² +30S +225= 725
-725 on both sides:
2S² +30S -500= 0
Divide both sides by 2:
S² +15S -250= 0
Factorise:
(S +25)(S -10)= 0
S +25= 0 or S -10= 0
S= -25 (reject) or S= 10
Sumbo's age cannot be a negative value hence -25 is rejected.
Substitute S= 10 into (1):
A= S +15
A= 10 +15
A= 25