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
enot [183]
3 years ago
6

(2x+1)(2x-1) find the product

Mathematics
1 answer:
VladimirAG [237]3 years ago
8 0
Difference of 2 perfect squares
a^2-b^2=(a-b)(a+b)
recognize that

(2x+1)(2x-1)
(a+b)(a-b)
therefor
product is
(2x)^2-(1)^2=
4x^2-1
You might be interested in
Question in attachment
ELEN [110]

Answer:

  • $20,000 at 8.5%
  • $10,000 at 10%

Step-by-step explanation:

There are a number of ways to solve mixture problems like this. Some are simple enough you can almost write down the answer. One I like uses a diagram to help you find the ratios of the components of the mix. You can do the same thing with a formula (without the diagram).

The basic idea is that you compute a ratio between two differences. The numerator is the difference between the average interest rate and the lower interest rate. Here, the average interest rate is 2700/30,000 = 0.09 = 9%. Then the numerator is 9% -8.5% = 0.5%

The denominator is the difference between the two interest rates of the investments: 10% -8.5% = 1.5%. And the ratio of these two values is ...

  0.5%/1.5% = 1/3

This is the fraction of the total investment that was invested at the higher interest rate:

  (1/3)×$30,000 = $10,000 . . . . was invested at 10%

Then the remaining amount, $20,000, was invested at 8.5%.

___

If you would prefer an equation, you can let x represent the amount invested at the higher rate. (That is the most convenient assignment of variables, as it keeps all of the numbers positive.) Then (30,000 -x) is the amount invested at the lower rate. The total amount of interest is ...

  10%(x) +8.5%(30,000 -x) = 2700

  x(10% -8.5%) = 2700 -8.5%(30000) . . . . . subtract 8.5%(30,000)

  x = (2700 -8.5%(30,000))/(10% -8.5%) . . . . divide by the coefficient of x

We have purposely left the expression unevaluated so that you can compare it to the math we described above. If you factor out 30,000 from the numerator of this fraction, you see the ratio that we described in words:

  x=30000\left(\dfrac{\dfrac{2700}{30000}-8.5\%}{10\%-8.5\%}\right)\\\\x=10,000

This tells us $10,000 was invested at 10%, and $20,000 was invested at 8.5%.

8 0
3 years ago
A DVD player is regularly priced at 79.95 and is on sale for 30% off. What is the discount?
evablogger [386]

Answer:

$2.40 or $77.55

Step-by-step explanation:

I don't know if you are asking for how much off or what, so I'm doing both

First, we have to find how much we have to take off or what is 30% of 79.95 so our equation is:

79.95 x 0.03 = 2.40

So 30% of 79.95 is $2.40

To find how much our new price sale is, we have to take that $2.40 off so our equation is:

79.95 - 2.4 = 77.55

So our discount price is $77.55

hope this helps:)

7 0
3 years ago
find the surface area of a regular square pyramid with a slant height of 17 m and a base perimeter of 44 m
iragen [17]
The side length is 18 ft 
7 0
3 years ago
Collins Middle School has 217 sixth grade students. If the sixth grade is 35% of the total school, how many students are in the
lbvjy [14]

Answer:620

Step-by-step explanation: lets say the total of school is X so:

X.35÷100=217

when we calculate this the answer will be  620

4 0
3 years ago
Read 2 more answers
Find the slope of the line that passes through (6,10) and (1,1)
Jet001 [13]

Answer:X2 = 5

Y2 = 4

ΔX = 4

ΔY = 3

θ = 36.869897645844°

Equation of the line:

y = 0.75x + 0.25

When x=0, y = 0.25

When y=0, x = -0.33333333333333

OR

X2 = -3

Y2 = -2

ΔX = -4

ΔY = -3

θ = 216.86989764584°

Equation of the line:

y = 0.75x + 0.25

When x=0, y = 0.25

When y=0, x = -0.33333333333333

5 0
3 years ago
Read 2 more answers
Other questions:
  • Complete the inequality.
    13·2 answers
  • Solve using dividing by 10 strategy. Show your work.
    12·1 answer
  • Let a set E ={0,2,4,6,8... } of non-negative even numbers and O = {1, 3, 5, 7, 9,...} of non-negative odd numbers then a) Cardin
    10·1 answer
  • Answer #2 becuase i dont knoe the answer worth 10 points
    13·1 answer
  • Bill and Lisa are surveying their classmates about their summer reading. Their questions are given below:
    9·2 answers
  • What is 2E + 40 - 16 ​
    14·1 answer
  • What is the relationship between ∠HIK and ∠JIK?
    5·1 answer
  • Use numerals instead of words. If necessary, use / for the fraction bar(s)
    6·1 answer
  • Solve for x <br><br> 5/6 = x/4
    13·2 answers
  • Solve the equation for the letter L: V = LWH (1 point) Select one: a. L = VWH b. L equals V times W over H c. L equals H over V
    5·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!