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PLEASE HELP !!!!
ivanna's earnings vary directly with the number of hours she works. suppose that she worked 7 hours yesterday and earned $77. if she earned $99 today, how many hours did she work today​

Respuesta :

Answer:

9 hr

Step-by-step explanation:

vary directly means you should think about a constant being multiply to one variable to get another variable.

So we have E=kH

where E=earnings and H=hours and k is the constant of proportionality

So they give us when H=7 we have E=77 giving us 77=k(7) which means the constant of proportionality is 11

So that means no matter what the E and H are k is 11

So we have the equation is E=11H

Replace E with 99 and solve for H

99=11(H)

So H=9

9 hours