10 POINTS! HELP ME! ALEBRA!!?!!?

1. 55% of 60 = 0.55*60
2. 28 is 70%. 3*28/7=84/7
3. 2*40
4. 0.35*140
5. 90/40.5=
6. 1
Remember that percent is just a foreign word for hundreds. So any percent = that number divided by 100. 200% means 2* something

And:
1. Fail. 36/6 = 6 and 12/9 = 4/3 or 1.333 -- Right is 8.
2. Success.
3. Success
4. Success
5. Fail. 9/5 is 1.8 and 3/15 is 0,18 or some such. Right is 1.
6. Fail. 4/5 is 0.8 and 3/6.5 is more like 0.45 or some such. Right is 3.75
Remember that you can calculate each number like in a triangle.
x
-- = z means x = z*y means that y=x/z
y

Don't worry about forgetting it, just make a small note when in doubt and scribble some easy numbers (just avoid 1 and 2). Like this;
3/6=0.5 means that 6=3/0.5 and 3=6*0.5

From the teaching side, substitute in
X for "what" or "what number"
= for "is"
and * (times) for "of"

so
1) What is 55% of 60
X = 55% * 60


2. 28 is 70% of what number?
28 = 70% *X

3. What is 200% of 40?
X = 200% * 40

etc.

Do you need me to work a few?

K, when writing out the problem from the question, leave it as is, don't try to rearrange the equation until you have it written in math form.
Let's take number 1:
1) What is 55% of 60
X = 55% * 60 - where I substituted the X for what, etc. But notice I put it straight down.
I assume you understand %? Just multiply time the number (55) and divide by 100, or you can use 55% = 0.55 (same thing)
so X= 55% * 60 or 0.55 * 60
X = 33

2) 28 is 70% of what number?
28 = 70% *X , so we want to get X on one side. So to do that divide both sides by 70%,
28/70% = 70%*X / 70% . like terms cross out on the right side. (70%/70% =1)
So 28/70% = X
28 / 0.70 = X
40= X

3. What is 200% of 40? This is like the first one:
X = 200% * 40 or 2.0 *40
X= 80

4. What is 35% of 140? Substitute in the math terms again:
X = 35% * 140
X = 0.35 *140
X = 49

5. What percent of 90 is 40.5? Ok
this is a different way of writing it, but don't worry, use the math term substitution we've been talking about:
X% * 90 = 40.5 , see just put the % in place of percent.
So let's get the numbers on one side. So divide both sides by 90.
X% *90 / 90 = 40.5/90 (The 90's on the left cross out 90/90=1)
X% = 40.5/90
X% = 0.45 or X = 45%

6. 2 is 200% of what number?
2 = 200% * X divide both sides by 200%
2/ 200% = 200% X / 200%
2 / 200% = X
2 / 2 = X
1 = X

How you doing Sissy Lou? If you need some help on these, just let me know.

2.) 3,160ft * 60 seconds * 60 mins = (11,376,000 ft/hour)/ 5,280 ft/mile = 2,154.54 miles/hour 3.) $572,632 year/12 months = $47,719.33 per month

1a)
60 x 55%
= 60 x 55/100
= 60 x 11/20
= 660/20
= 33

2a)
28 ÷ 70%
= 28 x 70/100
= 28 x 10/7
= 280/7
= 40

3a)
40 x 200%
= 40 x 200/100
= 40 x 2
= 80

4a)
140 x 35%
= 140 x 35/100
= 140 x 7/20
= 980/20
= 49

5a)
40.5/90 x 100%
= 4050/90 %
= 45%

6a)
2 ÷ 200%
= 2 ÷ 200/100
= 2 x 1/2
= 2/2
= 1

1b)
n/6 = 12/9
n = 6(12/9)
n = 72/9
n = 8

2b)
13/n = 39/27
n = 13/(39/27)
n = 13(27/39)
n = 351/39
n = 9

3b)
11.4/8 = 45.6/x
x = 45.6/(11.4/8)
x = 45.6(8/11.4)
x = 364.8/11.4
x = 32

4b)
16/41 = x/820
x = 820(16/41)
x = 13120/41
x = 320

5b)
x/5 = 3/15
x = 5(3/15)
x = 15/15
x = 1

6b)
4/5 = 3/x
x = 3/(4/5)
x = 3(5/4)
x = 15/4 (3.75)

55% of 60
= 55/100 x 60
= 33


let the number be a;
70% of a = 28
70/100 x a = 28
a = 28 x 100/70
a = 40


200% of 40
= 200/100 x 40
= 80


35% of 140
= 35/100 x 140
= 49


40.5/90 x 100%
= 0.45 x 100%
= 45%


let the number be a;
200% of a = 2
200/100 x a = 2
a = 4


n/6 = 12/9
n = 4/3 x 6
n = 4(2)
n = 8
therefore... u are wrong...

13/n = 39/27
13/n = 13/9
13 = 13/9(n)
n = 13/(13/9)
n = 9
therefore... u are right...

11.4/8 = 45.6/x
1.425 = 45.6/x
1.425x = 45.6
x = 45.6/1.425
x = 32
therefore... u are correct...

16/41 = x/820
16/41 x 820 = x
x = 16(20)
x = 320
therefore... u are right...

x/5 = 3/15
x = 1/5 x 5
x = 1
therefore... u are wrong...

4/5 = 3/x
4/5(x) = 3
x = 3/(4/5)
x = 15/4
x = 3.75
therefore... u are wrong...

1) What is 55% of 60?
0.55 x 60 = 33

2) 28 is 70% of what number?

28 = .70x

x = 28/.70
x = 40

3) What is 200% of 40?

2 x 40 = 80

4) What is 35% of 140?

.35 x 140 = 49

5) What percent of 90 is 40.?

90x = 40

x = 40/90

x = .4444 x 100 = 44.44%

6) 2 is 200% of what number?

2 = 2x

x = 2/2

x = 1

================
1)
n/6 =12/9

9n = 6 x 12

9n = 72

n = 72/9
n = 8

2)

13/n = 39/27
39n = 13 x 27

39n = 351

n = 9

3)
11.4/ 8 = 45.6/x

11.4x = 8 x 45.6

11.4x = 364.8

x = 32

4)
16/41 = x/820

41x = 16 x 820

41x = 13120
x = 13120/41

x = 320

5)

x/5 = 3/15

15x = 5 x 3

15x = 15

x = 15/15

x = 1

6)

4/5 = 3/x

4x = 5 x 3

4x = 15

x = 15/4

x = 3.75

CHECK your mistakes

Remember:

a/b = c/d ==>

ad = bc

1) 33
2) 40
3) 80
4) 49
5) 36.45
6) 1


1) wrong
2) yes
3) yes
4) yes
5) wrong
6) wrong

Remember that you want to get x on a side by itself to solve for it.
Just remember that you can multiple and divde numbers on both sides of the equation and keep the equation the same. For example number 2:

13/n = 39/27

You want to get n alone so first multiply each side by n:

n * (13/n) = n * (39/27) - the n will cancel on the left side so now you have

13 = 39/27 * n

Next we want to take the numbers out to solve for n:

13* 27 = (39/27) * n * 27 --> The 27 will cancel on the right leaving

13*27 = 39*n

Next

(13*27) / 39 = (39*n )/ 39 --> 39 cancels on the right leaving

(13*27) /39 = n

1. 55/100*60 = 33
2. 100/70*28 = 40
3. 200/100*40 = 80
4. 35/100*140 = 49
5. x/100*90 = 40.5
9x/10 = 40
9x = 405
x = 45 %
6. 100/200*2 = 1

1. 33
2. 40
3. 80
4. 49
5. 45%
6. 1

1. 8
2. 9
3. 32
4. 320
5. 1
6. 3.75

1. What is 55% of 60? = 33
2. 28 is 70% of what number? = 40
3. What is 200% of 40? = 80
4. What is 35% of 140? = 39
5. What percent of 90 is 40.5? = 45%
6. 2 is 200% of what number? = 1


You got three of them right. I think you understand enough to be able to get them all but just made some mistakes:

1. n/6 = 12/9 I put n=36: 9n = 72; n = 8
2. 13/n = 39/27 I put n=9: 39n = 13*27; n = 9
3. 11.4/8 = 45.6/x I put x=32: 11.4x = 8*45.6; x = 32
4. 16/41 = x/820 I put x=320: 41x = 16*820; x = 320
5. x/5 = 3/15 I put x=9: By inspection, x =1
6. 4/5 = 3/x I put x=6.5: 4x = 15; x = 3.75

How's that?