Question

A)(x+1)²+(x+2)²
B)(2x+1)²+(3x+1)²
C)5x-(2x+3)²
D)(x+5)²-x(x+3)

Answer 1

Ola 

a) (x + 1)² + (x + 2)² = x² + 2x + 1 + x² + 4x + 4 = 2x² + 6x + 5 

b) (2x + 1)² + (3x + 1)² = 4x² + 4x + 1 + 9x² + 6x + 1 = 13x² + 10x + 2

c) 5x - (2x + 3)² = 5x - (4x² + 12x + 9) = -4x² - 7x - 9 

d) (x + 5)² - x*(x + 3) = x² + 10x + 25 - x² - 3x = 7x + 25

Answer 2

a)

= (x + 1)² + (x + 2)²

= x² + 2x + 1 + x² + 2.2x + 4

= x² + 2x + 1 + x² + 4x + 4

= x² + x² + 2x + 4x + 1 + 4

= 2x² + 6x + 5
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b)

= (2x + 1)² + (3x + 1)²

= (2x)² + 2.2x.1 + 1² + (3x)² + 2.3x.1 + 1²

= 4x² + 4x + 1 + 9x² + 6x + 1

= 13x² + 10x + 2
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c)

= 5x - (2x + 3)²

= 5x - (4x² + 2.3.2x + 9)

= 5x - (4x² + 12x + 9)

= 5x - 4x² - 12x - 9

= - 4x² - 7x - 9
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d)

= (x + 5)² - x.(x + 3)

= x² + 2.5.x + 25 - x² - 3x

= x² + 10x + 25 - x² - 3x

= 10x - 3x + 25

= 7x + 25