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%.
-(3x-2)=-4(x+1)-4
-3x+2=-4x-4-4
-3x+4x=-4-4-2
x=-10
None of these answer choices are correct. The answer would be 51. 52+53=105
105-54=51
Answer:
3.92
×
10
^18
Step-by-step explanation:
(7 x 10^*9)(5.6 x 10^*8)
(7000000000)(560000000)
Move the decimal so there is one non-zero digit to the left of the decimal point. The number of decimal places you move will be the exponent on the
10
If the decimal is moved to the right, the exponent will be negative. If the decimal is being moved to the left, the exponent will be positive.
Answer:
the increase is by 2
Step-by-step explanation:
You can add 17 plus 2 or subtract 17 from 19.
