Y is inversely proportional to x. when y=7 , x=9
a) work out an equation connecting y and x
b) work out the value of y x=21

1.

2.

Step-by-step explanation:

Given

Variation: inverse Proportion

y = 7, x = 9

Required

- Write an equation connecting y and x

- Find y when x = 21

Given that thee variation is inversely proportional;

This implies that

Convert variation to equation

----------- Equation 1

Where k is the constant of variation

Substitute 7 for y and 9 for x in equation 1

Multiply both sides by 9

Substitute 63 for k in equation 1

Multiply both sides by x

Hence, the equation connecting x and y is

Solving for when x = 21

Substitute 21 for x in the above equation

Divide both sides by 21

1/5^2 = 7.56/45

hello from mrbilldoesmath!

answer:

the domain is the set { -2, 0, 2, 3}

discussion:

the domain is the set of x values in the ordered pairs (x,y). taking the x, or first component, of each ordered pair gives   -2, 0, 2, 3.

you,

mrb