Simplify 3x -2x -2x = 3x + -2x + -2x
Combine like terms: 3x + -2x + -2x = (3x + -2x +-2x) = -x
answer is: -x
Answer:
20 miles for 1 gallon.
Step-by-step explanation:
20 x 15 = 300
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%.
The annual return percentages will be evaluated using the formula:
A=P(1+r/100)^n
where:
A=amount
P=principle
r=rate
n=time
a] A=$500, P=$400, n=1 years
500=400(1+r)^1
solving for r we shall obtain:
1.25=1+r
hence
r=1.25-1
r==0.25
annual rate of investment is 25%
b] A=2500+100=$2600, P=$ 2000, n=1 year
hence
2600=2000(1+r)^1
2600/2000=1+r
1.3=1+r
r=1.3-1
r=0.3
annual rate of investment is 30%
Answer:
684 Hours.
Step-by-step explanation:
If the plane travelled that distance in 5 hours, then all you need to do is divide the distance by 5 to get the distance travelled in one hour. This is obviously presuming that the speed travelled was constant or that this is an average figure.
3420/5 = 684.
