Solve (a+?)(−2a+4) = −2a²−20a+48: Find the Missing Term

Question

Complete the missing element

(a+?)(2a+4)=2a220a+48 (a+?)(-2a+4)=-2a^2-20a+48

Video Solution

Step-by-Step Solution

To solve the problem, we'll follow these steps:

  • Step 1: Expand the expression (a+?)(2a+4) (a + ?)(-2a + 4) using the distributive property.
  • Step 2: Equate the resulting expression with the given form 2a220a+48 -2a^2 - 20a + 48 .
  • Step 3: Solve for the missing '?' that satisfies the equation.

Step 1: Expand the original expression:

(a+?)(2a+4)=a(2a)+a(4)+?(2a)+?(4)(a + ?)(-2a + 4) = a(-2a) + a(4) + ?(-2a) + ?(4)

Expanding gives us:

2a2+4a2a?+4?-2a^2 + 4a - 2a? + 4?

Step 2: Equate this with the provided expanded form 2a220a+48 -2a^2 - 20a + 48 :

2a2+4a2a?+4?=2a220a+48-2a^2 + 4a - 2a? + 4? = -2a^2 - 20a + 48

Step 3: Match the coefficients:

  • Compare the linear terms 4a2a?4a - 2a? with 20a-20a:
  • 42?=204 - 2? = -20 implies 4=20+2?4 = -20 + 2?
  • Solve for ? ? :
  • 2?=242? = 24 gives ?=12? = 12

The missing element is 12 12 .

Answer

12 12