(x + 3)(x + 4) expands to:
Ax2 + 12x + 12
Bx2 + 7x + 12
Cx2 + 12x + 7
Dx2 + 7x + 7
Answer & Solution
Correct answer: B. x2 + 7x + 12
1. Multiply each term of the first bracket by the second.
2. The x terms give 3x plus 4x, which is 7x.
3. The constants give 3 times 4, which is 12.
4. So the answer is x2 + 7x + 12.
_Source: NCERT Class 9 Mathematics, Ch 4 'Exploring Algebraic Identities'_
Related questions
After taking out 2, the expression 25p2 + 30pq + 9q2 is the square of:Expanding (a + b + c)2 gives how many squared terms?Who proposed the identity used to compute squares quickly in 750 CE?Using a2 - b2, the value of 51 squared minus 49 squared is:In (x + a)(x + b), the constant term is:In (x + a)(x + b), the coefficient of x is:(a + b)2 is verified using which property?An identity differs from an equation because it holds for: