Answer: The answer is − 5 plus per centimeter
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Answer: 187.5 tons of cement
Step-by-step explanation:
From the question, Sadie's Road Paving Company used 750 tons of cement to pave 4 miles of roadway. To calculate the number of cement on average that the company use per mile, we divide 750 tons of cement by 4 miles. This will be:
= 750 tons of cement/4
= 187.5 tons of cement
The company used 187.5 tons of cement per mile.
Answer:
A) (-3, 3) B) (-1, 1) C) (-2, 3)
Step-by-step explanation:
Answer:
a) y = 0.74x + 18.99; b) 80; c) r = 0.92, r² = 0.85; r² tells us that 85% of the variance in the dependent variable, the final average, is predictable from the independent variable, the first test score.
Step-by-step explanation:
For part a,
We first plot the data using a graphing calculator. We then run a linear regression on the data.
In the form y = ax + b, we get an a value that rounds to 0.74 and a b value that rounds to 18.99. This gives us the equation
y = 0.74x + 18.99.
For part b,
To find the final average of a student who made an 83 on the first test, we substitute 83 in place of x in our regression equation:
y = 0.74(83) + 18.99
y = 61.42 + 18.99 = 80.41
Rounded to the nearest percent, this is 80.
For part c,
The value of r is 0.92. This tells us that the line is a 92% fit for the data.
The value of r² is 0.85. This is the coefficient of determination; it tells us how much of the dependent variable can be predicted from the independent variable.
Answer:
It is a perfect square expression.
It factors to (x+2)^2
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Explanation:
The general format for a perfect square is
(a+b)^2 = a^2 + 2ab + b^2
Which can be seen through the use of the FOIL rule.
Compare x^2+4x+4 with a^2+2ab+b^2, and we have these three equivalences:
- x^2 = a^2 .... first terms
- 4x = 2ab .... middle terms
- 4 = b^2 .... last terms
Since x^2 = a^2, we can apply the square root to both sides to get a = x. Similarly, 4 = b^2 leads to b = 2. We could get b = -2, but that would mean 2ab = 2x*(-2) = -4x instead of 4x. So we'll stick with b = 2 instead.
Because a = x and b = 2, we then can say:
(a+b)^2 = a^2 + 2ab + b^2
(x+2)^2 = x^2 + 2*x*2 + 2^2
(x+2)^2 = x^2 + 4x + 4
Showing that x^2+4x+4 factors to (x+2)^2.
