Question

4/b-3.9 = 2/b+1

Answer 1

4
_____
b-3.9

Answer 2

That's what I figured. If you use parentheses to represent what is in the numerator and denominator when presenting fractions linearly , it would make interpreting them much clearer.

Answer 3

4/(b-3.9) = 2/(b+1)

This is the correct way to represent a fraction written linearly

Answer 4

Okay thanks. Can I have help on it? I know you distribute them

Answer 5

4(b+1) = 2(b-3.9)

Answer 6

Yes, correct

Answer 7

That's called cross multiplication

Answer 8

So now distributing the 4 and the 2, you get:

4b + 4 = 2b - 7.8

Answer 9

And then, after placing like terms on either side, you get

2b = -11.8

and then dividing both sides by two to isolate b, you get

b = 5.9

Answer 10

Any questions?

Answer 11

Umm on the combining terms.

Answer 12

when you said
So now distributing the 4 and the 2, you get: 4b + 4 = 2b - 7.8
Would I do it from left to right? so 4b-2b?

Answer 13

That's where I always become stuck at.

Answer 14

4b - 2b = -7.8 - 4

It really doesn't matter which side it's on. Just as long as you actually do it. You know that 4b and 2b are like terms

You know that 7.8 and 4 are like terms

The only thing needed to do is make sure you do the proper operation when placing them on their appropriate sides.

Answer 15

First you subtract 2b from both sides like so:

4b + 4 = 2b - 7.8
-2b -2b
-----------------
2b + 4 = -7.8

Then you subtract 4 from both sides like so:

2b + 4 = -7.8
- 4 -4
-----------------
2b = -11.8


Then you solve for b

Answer 16

Thank you so much!! This helps sooooooooooooo much!!!!!!! :DD

Answer 17

Yeah, I figured that maybe you hadn't seen that before so I went ahead and did it.

Answer 18

Thanks. Yeah my book does it differently and I never got it.

Answer 19

Yeah, sometimes books can present a different perspective that isn't always the best way to present certain concepts.

Answer 20

If you continue take higher and higher levels of math, you'll find that some books are really good at presenting concepts, and some books are not nearly as good at all.

Answer 21

I see that now. Thanks so much!

Answer 22

Aren't you going to give me a medal for my hard work?

Answer 23

I'm so sorry! Thanks for reminding me!

Answer 24

I gave you a medal because you know how to cross multiply :D

Answer 25

Aaaw. Thanks!!!