Question

Tamara has two sisters. one of the sisters is 7 years older than Tamara. The other sister is 3 years younger than Tamara. the product of Tamara’s sisters’ ages is 24. How old is tamara?

Answer 1

Tamara is 5 years old.

Explanation:

We can find Tamara's age by making expression in term of x. It is given that 1st sister is 7 years older and 2nd sister 3 years younger. So we can start making expressions :

Let x be Tamara's age,

Older sister,

x + 7

Younger sister,

x - 3

Given that the product of Tamara's ages is 24 which means you can multiply both of the sister together :

1st × 3rd = 24

(x+7)(x-3) = 24

x² - 3x + 7x - 21 = 24

x² + 4x - 21 = 24

Now, we have to solve the expression by factorisation :

x² + 4x - 21 = 24

x² + 4x - 45 = 0

(x+9)(x-5) = 0

x = -9(rejected)(age cannot be negative number)

x = 5

Answer 2

5

Explanation:

24=x+(x-3)+(x+7)