Question

Solve the equations below. Give exact solutions only. Show your work.

Answer 1

Answer:

A. 5x² - 7 - 72 = 0

5x² - 79 = 0

x = ± √-4ac / 2a

x = ± √- 4 (5) (-79) / 2 (5)

x = ± √ 1580 / 10

x = ± 39.749/10

x = + 39.749/10 x = -39.749/10

= 3.9749 = - 3.9749

B. x² + 2x - 5 = 0

x = - b ± √b² - 4ac / 2a

= - 2 ± √2² - 4 (1) (-5) / 2 (1)

= - 2 ± √4 + 20 / 2

= - 2 ± √ 24 / 2

x = - 2 + 4.898 /2 x = - 2 - 4.898 / 2

= 2.898/2 = -6.898/2

= 1.449 = - 3.449

C. 3x² + 2x - 4 = 0

x = - b ± √b² - 4ac / 2a

= - 2 ± √2² - 4 (3) (-4) / 2 (3)

= - 2 ± √4 + 48 / 6

= - 2 ± √ 52 / 6

x = - 2 + 7.211 /6 x = - 2 - 7.211 / 6

= 5.211/6 = - 9.211 /6

= 0.869 = - 1.535

Hope that helps

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