Suppose y varies directly as x, and y=80 when x=16 . which of the following statements is true?

a. the constant of variation is 5.

b. the variable y does not vary directly with x.

c. the constant of variation is -5.

d. the constant of variation is 1/5.

The following answer is B because it shows that it has to multiply the x - axis by the slope (5) to make sure that it can be equat to the y - axis.

y = 5x
y =5(16)
y = 80

(x, y) = (16, 80)

First step is to get rid of the square root. remember that a square root is the same as raising to the (1/2) power. see below: multiply exponents per exponent rules to get: remember you subtract exponents from the denominator and add exponents in the numerator so: simplify further: so a is the correct choice. if you don't understand this google exponent rules and it will you understand. look at the image results.