Question

Y y is inversely proportional to x.
when y=7, x=9

a)Work out and equation connecting y and x
b)Work out the value of y when x=21

Answer 1

a) Equation become xy=1 and the second part answer is b) y=1/21

Answer 2

Answer: y=3

Step-by-step explanation:

y=k/v (this is the needed equation)

7=k/9 (substitute numbers in)

7x9=63 (get k on its own)

y=63/x (now substitute new number in)

y=63/21= 3 (use info given to find answer)