If y varies inversely as x and y = 139 when x = –12, find y when x = 4. Round your answer to the nearest hundredth, if necessary.

-417

Step-by-step explanation:

Two variables x,y are inversely proportional to  each other when there exists a relationship between them as follows:

So, the product of the two variables is constant.

In this problem, at the beginning we have:

x = -12

y = 139

So, the  value of the constant product of the two variables is

Now we can find the value of y when

x = 4

In fact, using again the original equation and re-arranging it, we have:

honesty mood

step-by-step explanation:

b. 1.25 hr

step-by-step explanation:

if you have a constant speed of 60 mph, then you have a ratio between 60 mi. to 1 hr. dividing both sides by 60 we get the ratio

1 mi. to

then mult. both sides by 75 we get the ratio

75 mi. to

simplifying we get

75 mi. to

or 1.25 hr.