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%.
Answer:
b-3x+19
Step-by-step explanation:
you have to open the bracket so 3*x=3x
3*3=9
therefore;3x+9+10=3x+19
Step 1 = Distributive Property ( multiplying the 2 by each term in parenthesis)
Step 2 = Addition Property ( adding like terms)
Step 3 = Addition Property (adding 34x to each side)
Step 4 = Division Property. ( dividing both sides by 17)
Answer:
9
Step-by-step explanation:
So there's 3 1's, 2 2's, 2 3's, 1 4, 2 5's, a 6, a 7, an 8, 2 0's, and no 9's.