Hi there!
So, our two equations are:
2x + 3y = 20 and
-2x + y = 4
We can see that the x's will cancel out because they're the same number, opposite signs. Then we're left with 4y = 24.
Divide 24 by 4, which is 6.
y = 6, then we plug that in to the first equation for y:
2x + 3(6) = 20
2x + 18 = 20
2x = 2
x = 1
So, she made her first mistake when adding the equations, adding 20 and 4, she somehow got 16.
The solution to the system is (1,6).
I hope I helped!
The freezing point of water.
Answer:
21 cm
Step-by-step explanation:
The perimeter is the length of the outside of a shape. In this case, we can simply add up all the edges and multiply by .5(the length of one edge).
Horizontal Edges: 22
Vertical Edges: 20
Total: 42
Perimeter = 
Answer:
You didn't give us the following answers
Step-by-step explanation:
Answer:
(78, 80)
Step-by-step explanation:
Given a normal distribution :
Mean = 79 seconds
Standard deviation = 0.5 seconds
Using the empirical rule :
95% of her finishing times :
According to the empirical rule, 95% represents 2 standard deviations from the mean that is ± 2 standard deviations from the mean score or value.
Hence ;
The interval will be defined as ;
Mean ± 2(standard deviation)
79 ± 2(0.5)
79 ± 1
(79 - 1) ; (79 + 1)
78 ; 80
