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1 year ago

Complete the square to solve the equation below. check all that apply. x^2 + 8x - 1 = 19

Mathematics

2 answers:

Andreas93 [3]1 year ago

8 0

X=-10,x=2.I hope this helps.

Art [367]1 year ago

6 0

Answer:

B and D

Step-by-step explanation:

First take the equation and subtract 19 on both sides. You get x^2+8x-20=0

using the quadratic formula you get x= (-8 + or - root (8^2 -4(1)(-20)))/ 2(1)

simplify it and you get x= (-8 +or- 12) / 2

Separate the equation into two and you get (-8 + 12) / 2 and (-8 - 12) / 2

first one gives: 4/2=2

second gives -20/2=-10

answer x=-10,2

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On his outward journey, Ali travelled at a speed of s km/h for 2.5 hours. On his return journey, he increased his speed by 4 km/

den301095 [7]

Answer:

3.08 km/h.

Step-by-step explanation:

We know that,

$Speed=\dfrac{Distance}{Time}$

Ali traveled at a speed of s km/h for 2.5 hours.

Let d be the distance and t be the time.

$2.5=\dfrac{d}{t}$

$2.5t=d$ ...(1)

On his return journey, he increased his speed by 4 km/h and saved 15 minutes. So, distance is d and times is t-15.

$4=\dfrac{d}{t-15}$

$4(t-15)=d$ ...(2)

From (1) and (2), we get

$4(t-15)=2.5t$

$4t-60-2.5t=0$

$1.5t=60$

$t=40$

Put t=40 in (1).

$d=2.5(40)=100$

So, t=40 and d=100.

Now,

Total distance = d + d = 100 + 100 = 200

Total time = t + t - 15 = 40 + 40 - 15 = 65

So, the average speed is

$\text{Average speed}=\dfrac{\text{Total distance}}{\text{Total time}}$

$\text{Average speed}=\dfrac{200}{65}$

$\text{Average speed}\approx 3.08$

Therefore, the average speed is 3.08 km/h.

3 0

3 years ago

n Juanita's Art History class Quizzes are worth 15% of the final grade, Exams are worth 55%, Projects are worth 25%, and Attenda

kvv77 [185]

Answer:

90.75%

Step-by-step explanation:

Given;

Of the total final score;

Quizzes = 15%

Exam = 55%

Project = 25%

Attendance = 5%

Resolving the values of each section of the total score;

she had perfect attendance to class. 100% attendance;

Attendance = 5% of total score

She got extra credit on her project with a score of 26 out of 25 possible points.

Project = 26/25 × 25% = 26%

80, 85, and 96 on the first three exams,each worth 100 points;

Total exam score = 80+85+96 = 261 out of 300

Of the total score;

Exam = 261/300 × 55% = 47.85%

At mid-semester Juanita scored 119 out of 150 points on quizzes.

Quizzes = 119/150 × 15% = 11.9%

Total exam score is;

= Quizzes+exam +project+attendance

= 11.9% + 47.85% + 26% + 5%

= 90.75%

3 0

2 years ago

3+-1/1/3 the first half is 3+-1 the second half is 1/3

kolbaska11 [484]

$\bf \cfrac{3\pm1}{\frac{1}{3}}\implies 
\begin{cases}
\cfrac{3+1}{\frac{1}{3}}\\\\
\cfrac{3-1}{\frac{1}{3}}
\end{cases}\\\\
-------------------------------\\\\$

$\bf \cfrac{3+1}{\frac{1}{3}}\implies \cfrac{4}{\frac{1}{3}}\implies \cfrac{\frac{4}{1}}{\frac{1}{3}}\implies \cfrac{4}{1}\cdot \cfrac{3}{1}\implies \cfrac{4\cdot 3}{1\cdot 1}\implies \cfrac{12}{1}\implies \boxed{12}
\\\\\\
\cfrac{3-1}{\frac{1}{3}}\implies \cfrac{2}{\frac{1}{3}}\implies \cfrac{\frac{2}{1}}{\frac{1}{3}}\implies \cfrac{2}{1}\cdot \cfrac{3}{1}\implies \cfrac{2\cdot 3}{1\cdot 1}\implies \cfrac{6}{1}\implies \boxed{6}$

6 0

3 years ago

Lester’s car can go 15.4 miles on 1 gallon of gas. How far can he go on 0.7 gallon?

MAVERICK [17]

Answer:

He can go 10.78 miles

Step-by-step explanation:

This problem can be solve by creating a proportion, knowing that 15.4 miles is to one gallon the same as "x" miles (our unknown) is to 0.7 gallons. This can be set in math terms as the equation that relates these two ratios of miles per gallon:

$\frac{15.4\,miles}{1\,gallon} =\frac{x }{0.7\,gallon}$

and to solve for the unknown number of mile, we multiply both sides of the equation by "0.7 gallon" in order to isolate our unknown:

$\frac{15.4\,miles}{1\,gallon} =\frac{x}{0.7\,gallon}\\\frac{15.4\,miles\,*\,0.7\,gallon}{1\,gallon} =x \\x=10.78\,miles$

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3 years ago

There is a small pond which is 8 metres long, 4 metres wide and 2 metres deep. What is the volume of the pond?

Rama09 [41]

8 x 4 x 2 = 64
Therefore the volume of the pond is equal to 64m³

5 0

3 years ago

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