Test: Factorisation of Polynomials - Class 9 MCQ

Factors of a² + ab + bc + ca

• Step 1: Factor out common terms

Given expression: a² + ab + bc + ca

= a(a + b) + c(b + a)

= a(a + b) + c(a + b)

• Step 2: Factor by grouping

= (a + c)(a + b)

Therefore, the factors of a² + ab + bc + ca are (a + c)(a + b).

Correct answer is A.

The given expression is 2x(x + 2y) + 3x(2x - 3y).
To expand this expression, we distribute the terms inside the brackets:
1. 2x(x + 2y) = 2x² + 4xy
2. 3x(2x - 3y) = 6x² - 9xy
Adding the two results together we get:
2x² + 4xy + 6x² - 9xy = 8x² - 5xy
Therefore, the correct expansion of the expression is 8x² - 5xy, which matches option A.

The two numbers that add up to 14, and multiply to 45 and 9 and 5.

(x+5)(x+9)

y² – 4 y –21​
 y² – 7 y + 3 y –21​
 y (y – 7) – 3 (y – 7)
(y –​ 7) (y – 3)

P(x) = ײ - 6×+p
p (2)= (2)²-6 (2) +p
4- 12 + p = 0
-8 + p = 0
p = 8