Question

resolva as equações incompletas do 2° Grau:
10) 2x2 - 32 = 0
11) 5x2 - 50 = 0
12) 2x2 + 18 = 0
13) x2 + 7x=0
14) 5 x2 + 4 x = 0
15) 9x² - 4=0
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Answer 1

10) 2x² - 32 = 0

∆ = 0² - 4 2 -32

∆ = 256

- 0 ± √256 / 2.2

0 ± 16 / 4

±16/4

x' = 16/4 = 4

x" = -16/4 = -4

11) 5x² - 50 = 0

∆ = 0² - 4 5 -50

∆ = 1000

x' = √10

x" = -√10

12) 2x² + 18 = 0

∆ = 0² - 4 2 18

∆ = -144, não tem raiz real.

13) x² + 7x=0

∆ = 7² - 4 1 0

∆ = 49

- 7 ± √49 / 2.1

-7 ± 7 / 2

x' = 0

x" = -14/2 = -7

14) 5x² + 4x = 0

∆ = 4² - 4 5 0

∆ = 16

- 4 ± √16 / 2.5

-4 ± 4 / 10

x' = 0

x" = -8/10 = -4/5

15) 9x² - 4 = 0

∆ = 0² - 4 9 -4

∆ = 144

- 0 ± √144 / 2.9

±12 / 18

x' = 12/18 = 2/3

x" = -12/18 = -2/3