I think the correct answer is C. Since a=πr², in order to get the area to become 1/4 of what it was previously, the radius needs to be cut in half to make the divide that side by 4. a=π(r/2)²=πr²/4 and will therefore multiply the area by 1/4.
KX = x+4 so solve for k.
Divide both sides of the equation by x and you get K=4.
Plug it in, and you get (4)(7)=28
Your answer is 28.
The to this question is that it is a function
Upon formation of an equation from a given pattern, we know how the variables in the patter are related. Using the equation, we can find the value of one of the missing variables if the rest are known and also predict the values of the pattern at given conditions.
An example:
y = 2x + 5
if we are to predict the value of y at x = 3, we simply substitute 3 into x
y = 2(3) + 5
= 11
