Thread: percent

the cost of the meal is 21.60 with a tip. how much is the meal without the tip? let x = cost of meal without tip
the tip is 20% of x or 0.2x
together, x + 0.2x =21.60
1.2x = 21.6
x = 18 I obviously am lacking in my percents, and or decimals because I think I know how to add and subtract but still do not realize how 21.60 - 0.2 equals 18. easy question I know I just dont see it

Originally Posted by Leona_Marie

the cost of the meal is 21.60 with a tip. how much is the meal without the tip? let x = cost of meal without tip
the tip is 20% of x or 0.2x
together, x + 0.2x =21.60
1.2x = 21.6
x = 18 I obviously am lacking in my percents, and or decimals because I think I know how to add and subtract but still do not realize how 21.60 - 0.2 equals 18. easy question I know I just dont see it

x = 18 ; that is the price of your meal without the tip.

0.2x = (0.2)(x) = (0.2)(18) = 3.6 <-- The value of the tip.

Originally Posted by janvdl

x = 18 ; that is the price of your meal without the tip.

0.2x = (0.2)(x) = (0.2)(18) = 3.6 <-- The value of the tip.

having not known the answer. how would yo solve this equation
x + 0.2x x I believe means pertcent =21.60

Originally Posted by Leona_Marie

having not known the answer. how would yo solve this equation
x + 0.2x x I believe means pertcent =21.60

We pay for a meal (x) and give a 20% tip (0.2x)

So:

x + 0.2x = 21.60
1.2x = 21.60
x = 18

Now we know the tip is 20% of x, which is 18. And then it's a simple matter of calculating 20% of 18.

Originally Posted by janvdl

We pay for a meal (x) and give a 20% tip (0.2x)

So:

x + 0.2x = 21.60
1.2x = 21.60
x = 18

Now we know the tip is 20% of x, which is 18. And then it's a simple matter of calculating 20% of 18.

can you work the prob as follows , meaning the mechanics of 1.2x

Originally Posted by Leona_Marie

can you work the prob as follows , meaning the mechanics of 1.2x

I'm sorry. I don't know what you mean.

Originally Posted by janvdl

I'm sorry. I don't know what you mean.

somehow Ive lost somethig ok I dont mean to belabor but. I guess I need to pinpoint the question. x is the price of the meal without the tip yes. this $18. the tip is 20%. you said that 20% is 3.6. 0.2% =0.2x. so 0.2x + x should be 21.60 I would try to use my rules like x +0.2x - 0.2x =21.06 -0.2x if this is correct... than how do you -0.2x from 21.60 sorry if I dont understand the mathmatics or mechanics of 21.60
0.20
=21.40 help

Originally Posted by Leona_Marie

the cost of the meal is 21.60 with a tip. how much is the meal without the tip?
Let x = cost of meal without tip
The tip is 20% of x or 0.2x
Together, x + 0.2x =21.60
1.2x = 21.6
x = 18

Hi Leona,

That's all good. Did you do that yourself or was that an example out of the book?

Originally Posted by Leona_Marie

I obviously am lacking in my percents, and or decimals because I think I know how to add and subtract but still do not realize how 21.60 - 0.2 equals 18. easy question I know I just dont see it

The next step is to combine the "like terms" on the left side of the equation. No need to move anything to the right side. Your variable is already isolated on the left. Just add 1x + 0.2x to get 1.2x.



Now, all that's left to do is divide both sides of the equation by 1.2 in order to have x completely alone on the left side and the solution on the right side.





You need to practice more on general equation like this. Take a look at this tutorial here that's run by a friend of mine: Solving Linear Equations: 'One-Step' Equations

thank you thats the answer I was trying toget . 1.2 x 21.60 is 18
and yes the equation comes from a book, but the x + 1.2 -1.2 = 21.60 -1.2 is mine but Im not sure because to get the answer, I x 1.2 by 21.60
can you tell me more? possibly a short cut

Originally Posted by Leona_Marie

thank you thats the answer I was trying toget . 1.2 x 21.60 is 18

This is wrong. You do not multiply here. You divide

Originally Posted by Leona_Marie

and yes the equation comes from a book, but the x + 1.2 -1.2 = 21.60 -1.2 is mine

If it's yours, take it back because that's not the way to do it. On the left side of the equation , you have two terms with an x in them. Combine them. That means add. What do you get? 1x + 0.2x = 1.2x. Do nothing to the amount on the right side.

Originally Posted by Leona_Marie

but Im not sure because to get the answer, I x 1.2 by 21.60

No you don't. You divide as I stated before. Did you go to the link I suggested? I think you need to practice more on these types of equations to understand the flow.