Which 2 numbers add up to 8, but multiply to get 40?

Question

04-02-2016
Mathematics

contestada

Which 2 numbers add up to 8, but multiply to get 40?

Respuesta :

Otras preguntas

After Gulliver captures the Blefuscudian ships, what does the emperor of Lilliput want Gulliver to do? attend a celebration party in honor of the victory captur

WILL GIVE BRAINLIESTKarishma is reading "The Tell-Tale Heart." She reads an excerpt, looks for clues, and makes a prediction about what happens next. Read the s

Find the number of integers n that satisfy n^2 < 100.

A retailer purchased a mobile for Rs 3, 250 and SOLd it at 4%. LOSS

How many grams of boiling water must be added to an insulated cup containing 19 grams of ice, at 0oC, to completely melt the ice

2019 2018 2017 2016 2015 Sales $ 282,880 $ 270,800 $ 252,600 $ 234,560 $ 150,000 Cost of goods sold 128,200 122,080 115,280 106,440 67,000 Accounts receivable 1

What happens to the price of a three-year annual coupon paying bond with an 8% coupon when interest rates change from 8% to 8.96%

Convert 1101, to base 10.

Select the correct word from the Word Bank to complete the sentence. The cat used a piece of cheese to the mouse closer. Word Bank arid exuberance agate

Limestone, which contains the mineral calcite that fizzes in weak acid, may change due to heat and pressure into the metamorphic rock marble. What characteristi

Panoyin Panoyin · Answer 1 · 2016-02-04T23:09:39+01:00

x + y = 8
xy = 40

x + y = 8
x - x + y = -x + 8
y = -x + 8

xy = 40
x(-x + 8) = 40
x(-x) + x(8) = 40
  -x² + 8x = 40
-x² + 8x - 40 = 0
  -1(x²) - 1(-8x) - 1(40) = 0
   -1(x² - 8x + 40) = 0
-1 -1
x² - 8x + 40 = 0
x = -(-8) ± √((-8)² - 4(1)(40))
2(1)
x = 8 ± √(64 - 160)
2
x = 8 ± √(-96)
2
x = 8 ± 4i√(6)
2
x = 4 + 2i√(6)
x = 4 + 2i√(6) or x = 4 - 2i√(6)

  x + y = 8
4 ± 2i + y = 8
- (4 ± 2i) - (4 ± 2i)
y = 4 ± 2i
  (x, y) = (4 ± 2i, 4 ± 2i)

The two numbers that add up to 8 and multiply to 40 are 4 ± 2i.