Question

The population of a town is 5a${}^2$+3ab-9. If there are -2a${}^2$+ab males then find the number of females in the town.

• A. 5a²+2ab-3
• B. 7a²+3ab-9
• C. 2a²+2ab-1
• D. 7a²+2ab-9

Answer 1

The correct option is D

7a²+2ab-9

Population of the town = 5a${}^2$+3ab-9
Number of males in the town = -2a${}^2$+ab
Therefore, number of females in the town = 5a${}^2$+3ab-9-(-2a${}^2$+ab)
= 5a${}^2$+3ab-9+2a${}^2$-ab
= 5a${}^2$+2a${}^2$+3ab-ab-9
= 7a${}^2$+2ab-9