WAEC Further Mathematics 2023 Objective — Question 3

Question 3 of 40 from the West African Examinations Council (WAEC) Further Mathematics 2023 Objective paper, with the correct answer and a full explanation.

If sqrt(x) - 6/sqrt(x) = 1, find the value of x.

A. 9Correct
B. 16
C. 25
D. 36

Explanation

Multiplying through by sqrt(x): (sqrt(x))^2 - sqrt(x) - 6 = 0. Let sqrt(x)=u: u^2-u-6=0 => (u-3)(u+2)=0 => u=3 or u=-2. Since sqrt(x) cannot be negative, sqrt(x)=3, so x=9 (x=4 from u=-2 is extraneous and does not satisfy the original equation).

Sign up free to unlock

Score tracking
Practice history
Saved questions
Progress dashboard
Personalized sessions
Weak-topic breakdown

…and/or go further with premium services and No Ads.

Create free account

More questions from Further Mathematics 2023 Objective More Further Mathematics past papers