If x(a) = $a^2$ + 2a - 1, then x (8)-x (5) =?
43
45
14
3
Explanation:
Given, x(a) = $a^2$ + 2a - 1
=> x (8) = $8^2 $+ 2(8) - 1
=> 64 + 16 - 1 = 79
=> x (5) = $5^2$ + 2(5) - 1.
=> 25 + 10 - 1 = 34
Therefore, x (8) - x (5) = 79 - 34 = 45.