Looks like you would like to solve for y.

Remember that we would like to isolate y by performing the same operations on both sides of the equation until y remains on one side by itself.

To start add 1.2 to both sides.

This gives

-7.8 + 1.2 = y/2.45 - 1.2 + 1.2.

This lets us simplify to

-6.6 = y/2.45.

Now multiply both sides by 2.45.

This gives

-6.6*2.45 = y/2.45*2.45.

Now we have

-16.17 = y.

So these operations isolated y, and we can now read the solution, y = -16.17.

Hope that helped.

Robert B.

I'm sure I can help you. I'm just not sure exactly what area you need help with. Could you offer an example problem? "Doing proportions from decimals" needs some clarification is all.

11/20/12

Tiffany T.

can you help with story problems I am not good with them at all I got 4 I need help with here is the first one :A cologne can be made by mixing 2 drops of pure essence with 5 drops of distilled water. How much water should be used with 11 drops of pure essence?

drops of wate

11/20/12

Robert B.

To keep the same mixture we want the proportion to be the same.

(? DW)/(11 PE) = (5 DW)/(2 PE). Lets call the unknown x, as is customary.

x / 11 = 5 / 2.

Multiplying both sides by 11 gives

x / 11 * 11 = 5 / 2 * 11 or

x = 55 / 2 = 27.5.

So 27.5 drops of distilled water are required.

11/20/12

Tiffany T.

A recipe for spaghetti sauce requires four 16-ounce bottles of ketchup to make 2 gallons of sauce. How many bottles of ketchup are needed to make 18 gallons of sauce? (Hint: Read the problem very carefully.)

A recipe for brownies calls for 4 eggs and 11

2

cups of flour. If the recipe makes 15 brownies, how many cups of flour will be needed to make 160 brownies?

cups

The proper dosage of a certain medication for a 36-pound child is shown. At this rate, what would be the dosage for a 54-pound child?

oz

OK that will be it for today I hope my math tutor at Pierce College sugested this site for me so thank you so so much

11/20/12

Robert B.

If you would like more help from me, we could set up an online session. Check out my profile to contact me. I do lower my rate for online tutoring. Let me know if I can help. I'd be happy to assist you, and it'll be much easier than working through the comments. :)

11/20/12

Robert B.

I'll set up one more, but you'll have to solve it and the work on the rest.

X bottles / 18 gal = 4 bottles / 2 gal.

If you'd like any more help, please consider hiring me for an online session via Skype and scribblar.com, the online whiteboard application. It's a much more effective method for receiving tutoring online. Thanks!

11/20/12

Tiffany T.

yes thank you how about doing prportions from decimals

11/20/12