Math problems help(direct and inverse variation)

1.) x varies directly as y, write an equation that relates x and y, if x =56 when y=8

2.) x varies inversely as y, write an equation that relates x and y, if x=3 when y=9

Thank you..will give 10 points to who ever can help

1.) x varies directly as y, write an equation that relates x and y, if x =56 when y=8
x = ky
k = x/y = 56/8 =7
so x = 7y

2.) x varies inversely as y, write an equation that relates x and y, if x=3 when y=9
x = k/y
so k = xy = 3*9 = 27
so x = 27/y

1.) x varies directly as y, write an equation that relates x and y, if x =56 when y=8

x varies directly as y,
x= ky
k=x/y= 56/8=7
x=7y
2.) x varies inversely as y, write an equation that relates x and y, if x=3 when y=9
x varies inversely as y
x=k/y
k= xy= 3*9=27
x= 27/y

1. x varies directly as y can be shown as: x=ky

plug in the given numbers: 56=8k

divide both sides by 8

k=7

now your equation is: x=7y

2. x varies inversely as y can be shown as x=k/y

plug in the numbers given

3=k/9

multiply both sides by 9

27=k

now our equation is x=27/y

1.) x varies directly as y, write an equation that relates x and y, if x =56 when y=8
56/8=7=k

2.) x varies inversely as y, write an equation that relates x and y, if x=3 when y=9
3*9=27=k

~David

1/
x = ky , plug x = 56 , y = 8 ---> k = 7 , rule x = 7y
2/
x = k/y , and plug the point to find k

1. X56=Y8
2.X3=Y9