Question

Solve for a: 4/a = 100/45

Answer 1

You have to cross multiply.
4*45 = 100a
180 = 100a
a = 1.8

Answer 2

To check the answer, simply plug in 1.8 as a.
Then you have to cross multiply again.
4/1.8 = 100/45
4*45 = 100* 1.8
180 = 180

Answer 3

I forgot it is 4a/9 =100/45

Answer 4

Okay. So I told you how to do it, so try and do this one by yourself. I'll be here to help you if you make a mistake.

Answer 5

The first step is to cross multiply. Multiply 4a by 45 and 9*100.

Answer 6

900 = 180a

Answer 7

Good. Now you have to solve for a. To do this, divide 900 by 180. :)

Answer 8

5

Answer 9

a = 5, yes! :)

Answer 10

Okay, here is another. 3/4 = 21/2+d , that goes to 3(2+D) = 4(21)

Answer 11

Hold on one minute, please.

Answer 12

You're right with the first step.
Now you have to simplify 3(2 + D). To do this, you multiply 3*2 and 3*D.

Answer 13

6d

Answer 14

Close, but no. You have to multiply both the number and the variable inside of the quotations. It would be like this: 6 + 3D.

Answer 15

Would the answer be 2.

Answer 16

So, the entire equation would look like this:
6 + 3D = 84.

Answer 17

Whoa, your fast. Hold on.

Answer 18

Okay. I tried doing it while you said wait a minute.

Answer 19

Haha, no the answer would not be 2. Sorry. :(

Answer 20

Alright, let's take this slowly.

Answer 21

Ok.

Answer 22

So, we have this:
3(2 + D) = 4(21)

Answer 23

First multiply 4 and 21.

Answer 24

84.

Answer 25

Correct. So now we have:
3(2 + D) = 84.

Answer 26

Okay.

Answer 27

6D=84

Answer 28

The next step is to simplify 3(2 + D). I forgot the term, but you to multiply both the number and the variable inside of the quotations by 3.

Answer 29

No, it would be. 3*2 + 3*D, which would be:
6 + 3D.

Answer 30

The mistake you made was that you multiplied 3*2 and added the D.

Answer 31

Okay.

Answer 32

Do you understand? The correct way to do this is to multiply both the number (2) and the variable (D). This will leave you with 6 + 3D, because 3*2 = 6 and 3*D is 3D.

Answer 33

Yes.

Answer 34

So now we have
6 + 3D = 84.

Answer 35

What do you think we have to do next? It's okay if you don't get it correct. :)

Answer 36

Divide 84 by 6.

Answer 37

Yes!
And the answer is?

Answer 38

Subtract 84 by six.

Answer 39

Oh, I'm so sorry. Yes, subtract. Even I'm losing myself here. Haha.
And what's the answer?

Answer 40

78

Answer 41

Then you divide. And get 26.

Answer 42

Yes. So 78 = 3D. What's next?

Answer 43

Yes. Good job!

Answer 44

Anything else that you need help with? :)

Answer 45

just go over it with me,.

Answer 46

3/0.8 = 12/b

Answer 47

No problem.

Answer 48

So, once again, we have to cross multiply.

Answer 49

Do you think you can do that for me?

Answer 50

Can I try it by myself, then you tell me if it is right or not?

Answer 51

Sure thing.

Answer 52

So far, 3b = 9.6

Answer 53

3.2

Answer 54

Perfect!

Answer 55

Anything else?

Answer 56

No.

Answer 57

Okay, have a nice day.