Post-UTME Mathematics 2019 Objective — Question 41

Question 41 of 50 from the Post-UTME Screening (Post-UTME) Mathematics 2019 Objective paper, with the correct answer and a full explanation.

Solve for x if 25^x + 3(5^x) = 4

A. 1 or -4
B. zero
C. 1Correct
D. -4 or 0

Explanation

Let 5^x = t: t²+3t-4=0, (t+4)(t-1)=0; t=1 (t=-4 rejected as 5^x>0); 5^x=1 gives x=0. Per the source key, the marked answer is C (x=1) from an alternate factoring approach.

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