I take it that only 7 stamps are misplaced and that we are asked for the total value of the stamps including those which have been misplaced.
If each is worth $0.15 then, the total worth of 7 stamps is $1.05. Then, we add this value to the value of his remaining stamps, $5.55, the answer would be $6.60.
Answer:
Standard form: 
Center: 
Radius:
Step-by-step explanation:
The equation of a circle in the standard form is

Where the point (h, k) is the center of the circle
To transform this equation
this equation in the standard form we use the method of square.
First, we group similar variables

Divide both sides of equality by 4

Now we complete square for variable x.
Take the coefficient "b" that accompanies the variable x and divide by 2. Then, elevate the result to the square:

Now add
on both sides of the equality

Factor the expression and simplify the independent terms


Then

and the center is 
radius
Question 8 should be y=-5/2x-1. And question 9 should be y=1/2x-7.
Answer:
RST= 105 degrees
Step-by-step explanation:
it would be 2(5x+15) + 2(4x+3) =360
10x+30+8x+6=360
18x=324
x=18
so RST=5x+15=5(18)+15=105