All categories

4 years ago

Solve the equation by completing the square

Mathematics

1 answer:

Ilya [14]4 years ago

4 0

Answer:

We got the quadratic equation:

$x^2+8x-3=0$

Solving by completing the square:

$x^2+8x-3=0\\x^2+8x+16-16-3=0\\(x+4)^2-16-3=0\\(x+4)^2-19=0\\(x+4)^2=19\\x+4=\pm \sqrt{19} \\x=-4\pm \sqrt{19} \\\\x_{1} =-4+\sqrt{19} \\x_{2} =-4-\sqrt{19}$

Therefore, the answer is letter C

You might be interested in

Which are correct representations of the inequality –3(2x – 5) < 5(2 – x)? Check all that apply

Anna [14]

X > 5 Hope that helps

4 0

3 years ago

Read 2 more answers

M = y2 - y1 / x2 - x1 What is the slope of line JK? A) 5/9 B) 9/5 C) -5/9 D) -9/5

meriva

So
(x,y)

J is -4 to the right and 2 up so
(-4,2)

K is 5 to the right and -3 up
(5,-3)

(x,y)

x1=-4
y1=2
x2=5
y2=-3

M= $\frac{y2-y1}{x2-x1}$
M= $\frac{-3-2}{5-(-4)$
M= $\frac{-5}{5+4}$
M= $\frac{-5}{9}$

answer is C -5/9

3 0

4 years ago

Read 2 more answers

10 times 7 thousands in unit form

barxatty [35]

10 times 7 thousands in unit form would end up to be 70,000 because 10x7,000 if you carry out the zero one place would be 70,00

5 0

3 years ago

Paddy and Anna each invest $2000 for 5 years.

Serga [27]

Answer: r= 1.22

Step-by-step explanation:

Formula for amount with simple interest = $P(1+rt)$

, where

P= principal value , r= rate of interest , t = time.

Given: P= $2000, t= 5 years, r= 1.25% = 0.0125

$A=2000(1+0.0125\times5)\\\\=2000(1.0625)=2125$

Formula to compute compound amount : $P(1+r)^t$

$=2000(1+r)^5$

When both have same worth then

$2000(1+r)^5=2125\\\\\\ (1+r)^5=\dfrac{2125}{2000}\\\\\\ (1+r)^5=1.0625$

taking log on both sides , we get

$5\ln (1+r)=\ln 1.0625\\\\\\ 5\ln (1+r)=0.0606246\\\\\\ \ln (1+r)=0.012125\\\\\\ 1+r=e^{0.005266}\\\\\\ 1+r=1.0122\\\\ r=0.0122\\\\ \\ r=1.22\%$

Hence, Value of r= 1.22

6 0

3 years ago

Tina wants to save money for school. Tina invests $400 in an account that pays an interest rate of 7.5%.

Over [174]

Here's the given:
P=$400
i=7.5%
A=$8500

The formula used for this problem is:
A = P(1+i)^t

Manipulating the equation to arrive at t, we have:
t = ln(A/P) / ln(1+i)

Plugging in values:
t = ln($8500/$400) / ln(1+0.075)
<span>t = 42.26 years</span>

7 0

3 years ago