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juin [17]
2 years ago
10

Solve by completing the square: x^2+18x+45=0

Mathematics
1 answer:
MrRa [10]2 years ago
5 0

Answer:

 x = -3 , - 15

Step-by-step explanation:

<em>Given:</em>

<em>x² + 18x + 45 = 0</em>

<em>Solve:</em>

<em />x_{1,\:2}=\frac{-18\pm \sqrt{18^2-4\cdot \:1\cdot \:45}}{2\cdot \:1}

Simplify

-18\pm \sqrt{18^2-4\cdot \:1\cdot \:45=12

x_{1,\:2}=\frac{-18\pm \:12}{2\cdot \:1}

Separate the solution

x_1=\frac{-18+12}{2\cdot \:1},\:x_2=\frac{-18-12}{2\cdot \:1}

x_1=\frac{-18+12}{2\cdot \:1}=-3

x_2=\frac{-18-12}{2\cdot \:1}=-15

Thus, the answer are:

x=-3,\:x=-15

<u><em>Kavinsky</em></u>

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Therefore, the total amount accrued, principal plus interest,  from compound interest on an original principal of  $ 300.00 at a rate of 6% per year  compounded 2 times per year  over 0.5 years is $ 309.00.

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Using the formula

A\:=\:P\left(1+\frac{r}{n}\right)^{nt}

where

  • Principle = P
  • Annual rate = r
  • Compound = n
  • Time  = (t in years)
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Given:

Principle P = $300

Annual rate r = 6% = 0.06 per year

Compound n = Semi-Annually = 2

Time (t in years) = 1 years

To determine:

Total amount = A = ?

so using the formula

A\:=\:P\left(1+\frac{r}{n}\right)^{nt}

so substituting the values

A\:=\:300\left(1+\frac{0.06}{2}\right)^{\left(2\right)\left(1\right)}

A=300\cdot \frac{2.06^2}{2^2}

A=318.27 $

Therefore, the total amount accrued, principal plus interest,  from compound interest on an original principal of  $ 300.00 at a rate of 6% per year  compounded 2 times per year  over 1 year is $ 318.27.

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