Complete the missing element
(a+?)(−2a+4)=−2a2−20a+48
To solve the problem, we'll follow these steps:
- Step 1: Expand the expression (a+?)(−2a+4) using the distributive property.
- Step 2: Equate the resulting expression with the given form −2a2−20a+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)
Expanding gives us:
−2a2+4a−2a?+4?
Step 2: Equate this with the provided expanded form −2a2−20a+48:
−2a2+4a−2a?+4?=−2a2−20a+48
Step 3: Match the coefficients:
- Compare the linear terms 4a−2a? with −20a:
- 4−2?=−20 implies 4=−20+2?
- Solve for ?:
- 2?=24 gives ?=12
The missing element is 12.