Hello,
Let's suppose f(x)=3x+7
f(a-1)=3(a-1)+7=3a-3+7=3x+4
Answer B with a sign "++++++++++++++++++++++++++++"
Inverse variation equations take the following form:
y = a/x, where a is some constant
We know x=3, y=16 and x=6, y=8 satisfy the equation.
Let's find the value of a.
16=a/3
Multiply both sides by 3
16*3 = a
48 = a
Thus, the equation is:
y = 48/x
You can use the other values of x and y to test, but I'm sure this is the correct equation. :)
(This answer was sent on mobile, so please pardon any spelling errors I may have)
Answer:
We conclude that he purchased 20 rookie cards and 8 Hall of Fame cards.
Step-by-step explanation:
We know that Connor spent $66 on rookie cards and Hall of Fame cards. We know that rookie cards are four for six Hall of Fame two for nine.
Therefore, we calculate:

5·4= 20 rookie cards
4·2= 8 Hall of Fame cards
We conclude that he purchased 20 rookie cards and 8 Hall of Fame cards.