Question

Y is inversely proportional to x

Answer 1

A ) equation would be X = Z / Y
B ) if X = 9 ------------> Y = 1/7
X = 21 ----------> Y = ?
21*1/7 = 21/7 , 21/7÷9 = 21*9/7 = 27

so Y equal 27

Answer 2

Answer:

$y=\frac{63}{x}$

y=3

Step-by-step explanation:

y is inversely proportional to x

when y=7, x=9

When y is inversely proportional to x , then the equation is

$y=\frac{k}{x}$

where k is the constant of proportionality

y=7, x=9 plug in the values and find out k

$7=\frac{k}{9}$

Multiply 9 on both sides

63=k

an equation connecting y and x is $y=\frac{k}{x}$

$y=\frac{63}{x}$

b) work out the value of y when x=21

$y=\frac{63}{x}$

Plug in 21 for x

$y=\frac{63}{21}$

y=3