width (w) = w
Length (L) = 3w - 10
Area (A) = L x w
77 = (3w - 10)w
77 = 3w² - 10w
0 = 3w² - 10w - 77
0 = 3w² - 21w + 11w - 77
0 = 3w(w - 7) + 11(w - 7)
0 = (3w + 11)(w - 7)
0 = 3w + 11, 0 = w - 7
w = , w = 7 (width cannot be negative!)
w = 7
Length (L) = 3w - 10 = 3(7) - 10 = 21 - 10 = 11
Answer: width = 7 ft, Length = 11 ft
Answer:
y = 11
Step-by-step explanation:
y = 2(7) - 3
y = 14 -3
y = 11
Answer:
The answer is (10,55)
They both bowled for 10 hours and spent $55.
It will take me a long time to explain, but I'll give you the answer first, and then explain it later.
Step-by-step explanation:
Our system of equations are:
y = 4x + 15
y = 5x + 5
x = hours spent bowling
y = the total cost
I'll be using the substitution method, where y = 4x + 15 will be substituted into y = 5x + 5.
y = 4x + 15
y = 5x + 5
4x + 15 = 5x + 5
Now we solve
4x + 15 = 5x + 5
-5x -5x
-x + 15 = 5
- 15 - 15
-1x = -10 (the 1 in front is x is usually invisible)
/-1 /-1
x = 10
Now we substitute again to solve for y. *You can use either one of our original equations for this part y = 4x + 15 or y = 5x + 5.
y = 4x + 15
y = 4(10) + 15
y = 40 + 15
y = 55
We get our coordinates (10,55)
10 hours of bowling and $55 spent.
Hope that helps!
Answer:
0.989
Step-by-step explanation:
The formula for Margin of Error is:
z × Standard deviation/√n
Where
z = z score for 99% confidence Interval
= 2.576
n = 61 people
Standard deviation = $3
Hence,
Margin of Error
= 2.576 × 3/√61
= 0.989