Find the Missing Term in (a+?)(a+3) = a²+3a+2ab+6b

Question

Complete the missing element

(a+?)(a+3)=a2+3a+2ab+6b (a+?)(a+3)=a^2+3a+2ab+6b

Video Solution

Step-by-Step Solution

To solve this problem, we'll approach it by expanding and comparing terms:

  • Step 1: Apply the distributive property (FOIL method) to expand (a+?)(a+3)(a+?)(a+3).
  • Step 2: Compare each term in the expansion with the corresponding term in a2+3a+2ab+6ba^2 + 3a + 2ab + 6b.
  • Step 3: Identify and solve for the missing element.

Let's execute these steps:

Step 1: Consider the expression (a+b)(a+3)(a+ b)(a+3).

Using distributive property, it expands to:
(a+b)×(a+3)=a×a+a×3+b×a+b×3 (a + b) \times (a + 3) = a \times a + a \times 3 + b \times a + b \times 3 .

This gives us:
=a2+3a+ab+3b = a^2 + 3a + ab + 3b .

Step 2: Now, compare this expansion to the given expression a2+3a+2ab+6ba^2 + 3a + 2ab + 6b.

Step 3: From the comparison, we have:
- a2a^2 terms match.
- 3a3a terms match.
- For the abab term, abab should match 2ab2ab, implying b=2bb = 2b. Therefore, the missing term must contribute an additional bb, making it b+ab=2abb + ab = 2ab. Thus, b=2b = 2.
- For the constant term, 3b=6b3b = 6b, leading to the same conclusion.

Therefore, the solution to the problem is 2b 2b .

Answer

2b 2b