Question

4.x (x+3)-x=24+x

3.(x-5)+2.(2x-4)=x-1

Answer 1

4 . x (x + 3) - x = 24 + x

4x (x + 3) - x = 24 + x

4x² + 12x - x = 24 + x

4x² + 12x - x - x = 24

4x² + 12x - 2x = 24

4x² + 10x = 24

4x² + 10x - 24 = 0

a = 4

b = 10

c = - 24

∆ = b² - 4 . a . c

∆ = 10² - 4 . 4 . (-24)

∆ = 100 + 384

∆ = 484

x = - b ± √∆

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2a

x' = - 10 - 22

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2 . 4

x' = - 32

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8

x' = - 4

x" = - 10 + 22

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2 . 4

x" = 12 (÷4)

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8 (÷4)

x" = 3

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2

S = {-4 ; 3/2}

3 . (x - 5) + 2 . (2x - 4) = x - 1

3x - 15 + 4x - 8 = x - 1

3x + 4x - x = - 1 + 15 + 8

7x - x = - 1 + 23

6x = 22

x = 22 (÷2)

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6 (÷2)

x = 11

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3

S = {11/3}