Answer:
100 and 80
Step-by-step explanation:
Let x = be the first angle
x-20 is the second angle
They are supplementary so they add to 180
x+x-20 = 180
Combine like terms
2x-20 =180
2x-20+20 =180+20
2x= 200
Divide by 2
2x/2 = 200/2
x= 100
The first angle is 100 and the second is x-20
x-20 = 100-20=80
The two angles are 100 and 80
Answer:
Perimeter is 17.07
Step-by-step explanation:
We know that DF = EF = 5 cm, since D and E are the midpoints of AC and AB, both of which are 10 cm in length.
We need to use the Pythagorean theorem to get the length of DE.

So the perimeter of DEF is 5 + 5 + 7.07 = 17.07
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.
--------------------------------------------------------------------------------------------------------
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:
The probability is 1/5, or 20%
Step-by-step explanation:
There are 40 total items in the bag, and 8 of them are peanuts.
simplified is 