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.
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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%.
5-3(1/2x+2)=-7
-3(1/2x+2)=-7-5
(1/2x+2)=4
1/2x=2
x=4
just to give u an idea
They use percents less than one to get the the exact number
90ft by 7ft gives an area of:
90 x 7 = 630 sq ft
1/2 fl oz is needed for each square foot
630 x 1/2 = 315 fl oz required.
Answer:
0.08(50h)
Step-by-step explanation:
0.08(50h)+50h=
8/100(50h)+50h=
0.08(50h)+50h
It's 0.08 of 50h, so
0.08(50h)