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What is the missing term?

1. (x+2)^2 = __ +4x+4
2. (2x-3)^2 = 4x^2+__+9y^2
3. (3x+4)^2 = 9x^2 + 24x+__
4. (x-y)^2= __-2xy+y^2
5. (2x+3y)^2 = 4x^2+__+9y^2

User Umbreen
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1 Answer

4 votes

Answer:

see explanation

Explanation:

The general expansion of (a + b)² is

(a + b)² = a² + 2ab + b²

Applying this to the following expansions

(1)

(x + 2)² = x² + 2(2x) + 2² = x² + 4x + 4 ← missing term is x²

(2)

(2x - 3)² = (2x)² + 2(2x)(- 3) + 3² = 4x² - 12x +9 ← missing term is - 12x

(3)

(3x + 4)² = (3x)² + 2(3x)(4) + 4² = 9x² + 24x + 16 ← missing term is 16

(4)

(x - y)² = x² + 2(x)(- y) + y² = x² - 2xy + y² ← missing term is x²

(5)

(2x + 3y)² = (2x)² + 2(2x)(3y) + (3y)² = 4x² + 12xy + 9y² ← missing term is + 12xy

User Brandon Kreisel
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