Answer:
6.50
Step-by-step explanation:
You have to add/multiply 2.50 by 3 to get the total cost of the cards. 2.50*3=7.5. then, you need to add/multiply 3.00 by 2 to get 6. 7.5+6= 13.5. 20-13.5=6.50.
the change was $6.50
Answer:
y = 46
Step-by-step explanation:
Given y varies inversely as x then the equation relating them is
y = 
← k is the constant of variation
To find k use the condition y = 23 when x = 8 , then
23 = 
( multiply both sides by 8 )
184 = k
y = 
← equation of variation
When x = 4 , then
y = 
= 46
It is not differentiable at x=1 since the slope of the tangent line as x -> 1 from the right is 1 while the slope of the tangent line as x->1 from the left is -1
