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:
7
Step-by-step explanation:
We need to plug in -1 for x. Here's what we get:
multiplying two negative numbers gives us a positive number
= 7
Answer:
90 degree angle because a right angle is always 90 degrees
Answer:
1/7, 3/7, 4/7, 6/7
Step-by-step explanation:
There's like denominators(bottom number) so you would list the numerators(top number) from least to greatest.
Answer:
Solve the equation for
x by finding a
, b
, and c of the quadratic then applying the quadratic formula.
Exact Form:
x=
7
+
2
√
5
Decimal Form:
x
=
11.47213595
…
Step-by-step explanation:
