Answer: A; 6.3%
Step-by-step explanation:
Problem 1
For the first problem, we first want to find y so that we can plug it into the expression.
We can use elimination method for the system of equations to solve.
3x+3y=21
3x-y=5
We subtract both equations to eliminate x.
4y=16 [divide both sides by 4]
y=4
Now that we know y, we can plug it into the expression.
[divide]
[subtract]

We know that the answer is A.
--------------------------------------------------------------------------------------------------------
Problem 2
For the second problem, we need to know how to calculate percent error. The formula for precent error is
. We know that the exact value is 80 because the buyer was supposed to given 80. 75 is the measured value because that was what the buyer was given.
[subtract]
[solve absolue value]
[divide]
[multiply]

Since the problem said to round to one decimal place, we know that the answer is 6.3%.
Answer: 8
Step-by-step explanation:
6x-3=45
6x=48
x=8
if four points are collinear, that are also coplanar: This is true
If points lie in the same line. they must lie in the same plane
4 bowls of pasta would be served for twelve people.
4×3=12
Answer:
Yes
Step-by-step explanation:
If you add 87.84, 85, and 100 you get 272.84. Once you divide that by 3 you get 90.946, which would be your test average if you score 100 on your next test.