The old rate of pay is x and the new rate is y then we have:
y = 2x + 7
Y = 21
PART 1: 21 = 2x+7
Subtract 7 from each side:
14 = 2x
Divide both sides by 2:
X = 14 / 2
X = 7
PART 2: The internship pays $7 per hour.
Answer:

Step-by-step explanation:
a) 
b) 
c) 
d) 
e) 
f) 
Answer:
1600 integers
Step-by-step explanation:
Since we have a four digit number, there are four digit placements.
For the first digit, since there can either be a 5 or an 8, we have the arrangement as ²P₁ = 2 ways.
For the second digit, we have ten numbers to choose from, so we have ¹⁰P₁ = 10.
For the third digit, since it neither be a 5 or an 8, we have two less digit from the total of ten digits which is 10 - 2 = 8. So, the number of ways of arranging that is ⁸P₁ = 8.
For the last digit, we have ten numbers to choose from, so we have ¹⁰P₁ = 10.
So, the number of integers that can be formed are 2 × 10 × 8 × 10 = 20 × 80 = 1600 integers
Answer:
y=3/2x-4
Step-by-step explanation:
y=3/2x+b
-1=3/2(2)+b
-1=3+b
-4=b
y=3/2x-4
Honestly I don't know that is a really hard question