Question

Resolva as seguintes equação

Answer 1

a) 7x² - 28 = 0

x' = 0

7x - 28

7x = 28

x = 28 / 7

x" = 4

b) 4x² - 12x = 0

x' = 0

4x - 12

4x = 12

x = 12 / 4

x" = 3

c) 3x² - 7x + 2 = 0

delta = (-7)² - 4.(3).(2) = 49 - 24 = 25

x = ( - (-7) +- V25 ) / 2.3 = ( 7 +- 5 ) / 6

x' = ( 7 - 5 ) / 6 = 2 / 6 = 0,333...

x" = ( 7 + 5 ) / 6 = 12 / 6 = 2

d) x² - 25 = 0

x² = 25

Vx² = V25

x = 5