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
alisha [4.7K]
2 years ago
10

How do I solve this?

Mathematics
2 answers:
Elina [12.6K]2 years ago
7 0

Value of xis - 12.

Final Answer is 480

Step-by-step explanation:

Assume that:

First number = x

Second number = 20 - x

Putting the given conditions,

2x^{2} + 3(20 - x)^{2}

Putting the formula (a-b)²=(a²+2ab+b²) in (20-x)²,

2 {x}^{2} + 3(20^{2} - 2 \times 20 \times x +  {x}^{2})

=  > 2 {x}^{2} + 3(400 - 40x + x^{2})

Opening the brackets,

2 {x}^{2} + 3 \times 400 - 3 \times 40x + 3 \times  {x}^{2}

=  > 2 {x}^{2} - 1200 - 120x +  3{x}^{2}

=  > (2x^{2} + 3 {x}^{2}) - 120x + 1200

=  > 5 {x}^{2} - 120x + 1200

As \: x= -  \frac{b}{2a}

=  >  -  \frac{120}{2 \times 5}

=  >  -  \frac{120}{10}

=  >  - 12

Now substituting the value of x in 5x²-120x+1200,

=  > (5 \times {12}^{2} )-(120 \times 12)+1200

=  > (5 \times 144)-(1440)+1200

=  > 720 - 1440 + 1200

=  > 720 - (1440 - 1200)

=  > 720 - 240

=  > 480

mart [117]2 years ago
3 0
X + y = 20 Substitute
x by 2 y - 4 in x + y = 20 to obtain 2 y •
4 + y = 20 Solve for y to find y = 8 and
x = 2y - 4 = 12
You might be interested in
Susan was writing a paper for English, and she thought it was going to take her 4 hours to write. In fact, it took her 6.5 hours
Goryan [66]

Answer:

61.5%

Step-by-step explanation:

i could be wrong

7 0
3 years ago
Read 2 more answers
Which is a better deal on a $345 item: 40% off original price or 30% off and additional 15% at the register?​
Talja [164]

Answer:

345 - 40% = 207$

Step-by-step explanation:

(345 - 30%) - 15% = 205.3 (Better deal)

4 0
3 years ago
Read 2 more answers
What is the area of the figure?
natima [27]
The answer is 88 in sq


Explanation: you need to multiply the length a width of each shape then add them all together.
5 0
3 years ago
Read 2 more answers
Wes works at a science lab that conducts experiments on bacteria. The population of the bacteria multiplies at a constant rate,
Dmitry [639]

Answer:

Correct answer: at 2 p.m. the population was 10,000

                          at 3 p.m. the population was 50,000

Step-by-step explanation:

At 1 p.m. population was 2,000

At 2 p.m. or after  first hour, the population of bacteria increases

in this way 2,000 · k  

At 3 p.m. or after second hour, the population of bacteria increases

2,000 · k²

At 4 p.m. or after third hour, the population of bacteria increases 2,000 · k³

2,000 · k³ = 250,000 =>  k³ = 250,000 / 2,000 = 125

k = ∛125 = 5  => k = 5

At 2 p.m. or after  first hour, the population of bacteria was 2,000 · 5 = 10,000

At 3 p.m. or after second hour, the population of bacteria was 2,000 · 5² =

= 2,000 · 25 = 50,000

God is with you!!!

6 0
3 years ago
Please someone help with my math
Pepsi [2]

Answer:

1. .31

2. .68

3. .08

4. true???

5. 2.83

6. .75

7. true again??

8.  .09

9. 4.55

10 .10

11. 9.33

12. .92

13. 14.16

Step-by-step explanation:

i didnt really understand 4 and 7 sooo true?

6 0
3 years ago
Other questions:
  • What is the perimeter of trapezoid JKLM? j -7,4 k -4,4 m -8,3 l -2,3
    14·1 answer
  • All the correct answers please
    13·1 answer
  • Whats the main purpose of the frontal lobe on the brain?
    15·1 answer
  • Could u guys please find the area of this shape I am stuck
    5·1 answer
  • Round to nearest ten 6811.09
    7·2 answers
  • Find the midpoint of diagonal AC of ABCD
    6·1 answer
  • What is the x-value at which the graphs of y = x2 – 2x + 1 and y = x2 + 2x – 7 inter-<br> sect?
    15·1 answer
  • How much does a customer pay for an article marked at $50 if a sales tax of 6% is charged?
    12·1 answer
  • mean of 164,175,178,166,167,145,176,150,174,162,180,156,173,158,182,184,160,172,186,168,195,169,171,187,170
    12·1 answer
  • Craig is practicing his baseball pitching he kept track of the speed oI made a histogram at right can you tell the speed of each
    8·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!