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Virty [35]
3 years ago
12

a rectangular deck has a area of 320 ft squared. the length of the desk is 4 feet longer than the width. find the dimensions of

the desk. Solve by completing the square.
Mathematics
1 answer:
Anon25 [30]3 years ago
3 0
Because l•w= area, area= 320, l=w+4
width • (width +4)= 320

Distribute the multiplication over addition and move all to the left side.
w^2 +4w-320=0
(w-16)•(w+20)=0 yet, The product of two things is 0 if one is 0 or both are 0 so
w-16=0 so w=16 and
w+20=0 so w= -20

Now the width or length could not be negative so we discard the solution w=-20.

Answer
width= 16 inches
length =16+4=20

Verify
w•l=320
16•20=320✔️





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What are all of the possible classifications for a 3x3 system?
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Answer:

Consistent and Dependent  

Consistent and Independent  

Inconsistent and Independent

Step-by-step explanation:

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3 years ago
Read 2 more answers
given that (-3,-5) and (-1,-4) are points on the same line, find a point slope form of the equation for this line
posledela
The answer to the question

3 0
3 years ago
Twin brothers, Billy and Bobby, can mow their grandparent’s lawn together in 63 minutes. Billy could mow the lawn by himself in
Pepsi [2]

Answer:

<h2>140 minutes</h2>

Step-by-step explanation:

this problem focuses on the combined work rate

both can finish the work under 63 minute

let bobby mow the lawn in x minute

Billy will then mow the lawn in x-25 minutes

Let the completed job = 1 (a mowed lawn)

we can now apply the combined work formula for the two boys as

\frac{63}{x}+\frac{63}{x-25}=1

multiplying through by x(x-25 )we have

63(x-25)+63x= x(x-25)

open bracket we have

63x-1575+63x= x^2-25x

rearranging and collecting like terms we have

0=x^2-25x-63x-63x+1575 \\\\0=x^2-151x+1575 \\\\x^2-151x+1575=0

we can now use the quadractic formula

x=\frac{-b\frac{+}{} \sqrt{b^2-4ac} }{2a}

 

a= 1

b= -151

c= 1575

x=\frac{-(-151)\frac{+}{} \sqrt{151^2-4*1*1575} }{2*1}

x=\frac{-(-151)\frac{+}{} \sqrt{22801-6300} }{2} \\\\x=\frac{-(-151)\frac{+}{} \sqrt{16501} }{2} \\\\x=\frac{-(-151)\frac{+}{} 128.45}{2} \\\\

x=\frac{-(-151)+128.45}{2} \\\\\x=\frac{279.45}{2} \\\\x=139.72 \\\\\\x=\frac{-(-151)-128.45}{2}\\\\x=\frac{151-128.45}{2}\\\\x=\frac{22.55}{2}\\\\x=11.27

the first answer x= 139.72 approximately 140 minutes mins is correct for  Bobby's time

let us check

\frac{63}{140}+\frac{63}{140-25}=1\\\\\\0.45+\frac{63}{115} =1\\\\0.45+0.5478=1\\0.997 =1

we can see that the solution approximates to 1

8 0
4 years ago
Please help me this is due tonight
hram777 [196]
ANSWER:

Substitution prop of equality.

I'm not sure but I think this should be the answer.

Hope this helps! :)
8 0
3 years ago
what is the probability of hitting each target if it is assumed that a player’s throw will always hit the board? hint: the proba
solong [7]
Because the actual dimensions of the board and the target are missing, let us supply the missing values. 

Let:

radius of board = 6 inches
radius of target = 2 inches

Area of board = pi * r^2 = pi*6^2 = 36pi
Area of target = pi * r^2 = pi*2^2 = 4pi

Probability of hitting the target = 4pi / 36pi = 1/9

Therefore, there is a 1/9 chance of hitting the target on the board.
4 0
3 years ago
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