I am unsure about the very last problem but I can help with the first two
1) (y+1)+4
If we combine the numbers 1 and 4, we get +5 and can isolate the numbers from the variable.
This would give us

2) (6*r)*7
remember that we do not have to explicitly state 6*r
Instead, we can write it as 6r
this helps us get rid of the parentheses
now we can write it as

I hope this helps!:)
C is your answer buddy brainliest please
Explanation:
Kadisha's method works because 15% is 3 times 5%, and both amounts are computed on the amount of the bill before tax is added.
Answer:
The standard deviation of X is 0.7
Step-by-step explanation:
We are given the following distribution:
x: 0 1 2 3
P(x): 0.3 0.5 0.2 0.4
We have to find the standard deviation of X.
Formula:

Thus, the standard deviation of X is 0.7
Answer:
Step-by-step explanation:
<em>Perimeter is the sum of side lengths</em>
<u>Let's find the sides first</u>
- AB = √(-2- 2)² + (-4+1)² = 5
- BC = (2 - (-1)) = 3
- CD = √(-1- 2)²+(5-2)² = √18 = 3√2 = 4.24
- DE = √(-4 -(-1))²+(2-5)²= √18 = 3√2 = 4.24
- AE = √(-4-(-2)²+(2-(-4))²=√40= 2√10 = 6.32
<u>Perimeter is</u>
- P = 5 + 3 + 4.24 + 4.24 + 6.32 = 22.8 ≈ 23 rounded to the nearest whole number