All categories

2 years ago

If (3a + 3b + 1) (3a + 3b - 1) = 80, then what is a + b?

Mathematics

1 answer:

MrRa [10]2 years ago

4 0

Answer: a + b = 3 - maybe

Step-by-step explanation:

( 3a + 3b + 1 )( 3a + 3b - 1 ) = 80

Expand

9a² + 9ab - 3a + 9ab + 9b² - 3b + 3a + 3b - 1 = 80

Simplify

9a² + 9b² + 18ab - 1 = 80

move the 1 over

9a² + 9b² + 18ab = 81

divide by 9

a² + b² + 2ab = 9

not really sure after this part

move the 2ab over

a² + b² = 9 - 2ab

square root both sides

a + b =

simplify

a + b = 3 -

You might be interested in

A carpenter needs 9.3 feet of rope for a project. How much will the carpenter spend if the rope costs $3.82 per foot?

den301095 [7]

The total amount the carpenter will spend if the rope costs $3.82 per foot is $35.526

<h3>How to determine how much will the carpenter spend if the rope costs $3.82 per foot?</h3>

The length of rope is given as:

Length = 9.3 feet

The price per rope is given as:

Price per rope = $3.82 per foot

The total amount spent by the carpenter is calculated as:

Total amount = Length * Price per rope

Substitute the known values in the above equation

Total amount = 9.3 feet * $3.82 per foot

Evaluate the product

Total amount = $35.526

Hence, the total amount the carpenter will spend if the rope costs $3.82 per foot is $35.526

Read more about products at:

brainly.com/question/10873737

#SPJ1

4 0

1 year ago

Read 2 more answers

The Powerball lottery is played twice each week in 28 states, the Virgin Islands, and the District of Columbia. To play Powerbal

Alecsey [184]

Answer:

There are 3478761 ways to select the first 5 numbers

Step-by-step explanation:

As understood from the statement of this problem we assume that it does not matter the order in which the first 5 white balls are selected.

In this case it is a combination.

So, what we want to know is how many ways you can choose 5 white balls out of 55.

Then we use the formula of combinations:

$C(n, x) = \frac{n!}{x! (n-x)!}$

Where you have n elements and choose x from them.

Then we look for:

$C(55, 5) = \frac{55!}{5!(55-5)!}\\\\C(55, 5) = \frac{55!}{5!(50)!}\\\\C(55, 5) = 3478761$

6 0

2 years ago

Poncio walks 0.5 mile to school each day. Multiply the distance by 2 to find the total distance he walks each day.

Aleksandr [31]

Answer:

Step-by-step explanation:

.5 x 2 = 1

8 0

2 years ago

Can someone please help me

azamat

Given:

angle ECB=51 degrees

angle EOB = 2*angle ECB = 2*51 = 102 degrees = arc EAB

Also given minor arc AB = 72 degrees

therefore

minor arc EA = 102-72=30 degrees

5 0

3 years ago

Read 2 more answers

Can someone help please I need this asap

son4ous [18]

Answer:

PART:A

$10_P_4=5040$

PART:B

$6_C_2=15$

PART:C

$6_C_2=15$

Step-by-step explanation:

PART:A

When the four officers are chosen than the number of ways of doing this is:

$10_P_4$

since we have to choose 4 officers and also they need to be arranged according to their ranks.

Hence, the numbers of ways doing so is:

$10_P_4=\dfrac{10!}{(10-4)!}\\\\=\dfrac{10!}{6!}\\\\=10\times 9\times 8\times 7\\\\=5040$

PART:B

Now we have to choose 2 members out of the remaining 6 members so the we have to use combination since we have to just choose the members and do not have to rank them or in short we can say we do not have to arrange them.

Hence, the number of ways doing this is:

$6_C_2=\dfrac{6!}{2!\times (6-2)!}\\\\=\dfrac{6!}{2!\times 4!}\\\\=15$

Hence, the number of ways of doing this is: 15.

PART:C

Now this process of doing so is also same as the above.

Hence, the number of ways of doing so is: 15.

8 0

2 years ago