WAEC Mathematics 2025 Paper

Concept:Factorize the quadratic equation by splitting the middle term, then solve each linear factor.Explanation:The given equation is $3x^2 + 25x - 18 = 0$.Find two numbers whose product is $3 \times (-18) = -54$ and whose sum is $25$.These numbers are $27$ and $-2$, because $27 + (-2) = 25$ and $27 \times (-2) = -54$.Rewrite the middle term: $25x = 27x - 2x$.So the equation becomes $3x^2 + 27x - 2x - 18 = 0$.Group the terms: $3x(x + 9) - 2(x + 9) = 0$.Factor out the common factor $(x + 9)$: $(3x - 2)(x + 9) = 0$.Set each factor to zero: $3x - 2 = 0$ or $x + 9 = 0$.This gives $3x = 2$, so $x = \frac{2}{3}$, or $x = -9$.Answer:$x = -9$ or $x = \frac{2}{3}$, which is option B.