1answer.
Ask question
Login Signup
Ask question
All categories
  • English
  • Mathematics
  • Social Studies
  • Business
  • History
  • Health
  • Geography
  • Biology
  • Physics
  • Chemistry
  • Computers and Technology
  • Arts
  • World Languages
  • Spanish
  • French
  • German
  • Advanced Placement (AP)
  • SAT
  • Medicine
  • Law
  • Engineering
liubo4ka [24]
3 years ago
8

Solve x2 - 4x - 7 = 0 by completing the square. What are the solutions?

Mathematics
1 answer:
Roman55 [17]3 years ago
5 0

Answer:

x= 2 + √11 or x = 2 −√11

Step-by-step explanation:

I am going to complete the square step-by-step.

x² − 4x − 7=0

Step 1: Add 7 to both sides.

x² − 4x − 7+ 7 = 0 + 7

x² − 4x = 7

Step 2: The coefficient of -4x is -4. Let b = -4.

Then we need to add (b/2)² = 4 to both sides to complete the square.

Add 4 to both sides.

x² − 4x + 4 = 7 + 4

x² − 4x + 4 = 11

Step 3: Factor left side.

(x−2)² = 11

Step 4: Take square root.

x − 2 = ±√11

Step 5: Add 2 to both sides.

x − 2 + 2 = 2 ±√11

x = 2 ±√11

x= 2 + √11 or x = 2 −√11

You might be interested in
While Preparing For A Morning Conference, Principal Corsetti Is Laying Out 8 Dozen Bagels On Square Plates. Each Plate Can Hold
USPshnik [31]
We have 8 dozen bagels, or 8*12=96 bagels.  Each plate can hold 14 bagels, so we have enough bagels to fill 96/14=about 6.86 plates.  However, we cannot have a fraction of a plate, so we round up to have a total of seven plates.  To fill all seven plates fully, 7*14=98 bagels would be needed, which is two more than we have.

To summarize, Mr. Corsetti has seven plates of bagels, and would need two more bagels to fill the last one up.
6 0
3 years ago
What is the slope of the line in the graph below?<br> (look at picture)
attashe74 [19]
The answer is 3/4! Explanation: use slope formula
5 0
3 years ago
liam has 8 3/4 gallons of paint. he wants to use 2/5 of paint to paint his livingroom. how many gallons of paint will liam use?​
slava [35]

<u>Answer:</u>

Liam will use 3.5 gallons of paint to paint his living room

<u>Solution:</u>

Given that Liam has 8 \frac{3}{4} gallons of paint.

He uses \frac{2}{5} of paint to paint his living room

We need to find how many gallons of paint will Liam use

The gallons of paint Liam used can be found as follows:

Amount of paint Liam has = 8 \frac{3}{4} gallons  

Converting mixed fraction 8 \frac{3}{4} to decimal we get 8.75

Amount of paint used = 2/5th of available amount  

= \frac{2}{5} \times 8.75=3.5 \text { or } 3 \frac{1}{2} \text { gallons }

Hence Liam will use 3.5 gallons of paint to paint his living room

3 0
3 years ago
A bread recipe calls for 1/3 cup of butter. You want to make 1/2of a batch.
nordsb [41]
It would be 1/2 times 1/3 to get 1/6 cups of butter.
8 0
3 years ago
Read 2 more answers
What is the rate of change between (2,2) and (17,7)
choli [55]

Answer:

1/3

Step-by-step explanation:

(7-2)/(17-2)=5/15=1/3

5 0
3 years ago
Other questions:
  • Choose among these options the one that results in a graph that shows exponential decay. A. f(x) = 0.6(2)x B. f(x) = 3(0.7)x C.
    5·1 answer
  • Can you explain how to divid fractions so I can help my daughter.<br> 3/8 ÷ 2/3=
    14·2 answers
  • What are the solutions to log3x + log3(x2 + 2) = 1 + 2log3x?
    14·2 answers
  • Helpppppppppppppppppppppppppppppppp
    8·1 answer
  • In the diagram below DE is parallel to x what is the value of x
    10·1 answer
  • a swimming pool is three times as long as it is wide. the sidewalk around the pool is 72 yds long. determine the length and widt
    7·2 answers
  • In the broken china plate, CD = 8 cm, OY, the perpendicular bisector of CD, = 3 cm. What is the diameter of the plate?
    11·2 answers
  • What are the possible numbers of positive, negative, and complex zeros of f(x) = −3x4 + 5x3 − x2 + 8x + 4?
    7·1 answer
  • Fill in the blanks concerning the following quadratic function: f(x)=−x2−4x+5
    5·1 answer
  • (-3,3) 8 units down and 7 units right
    14·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!