Question

Which equations are equivalent to the given equation? 0.4y=10
Choose all answers that are correct.

A. 0.4y=10÷0.4
B. 0.4y÷0.4=10÷0.4
C. 0.4y*2.5=10*2.5
D. 0.4y÷0.4=10*0.4

Answer 1

First, what can you do to get y by itself?

Answer 2

I'm completely lost here.

Answer 3

Haha np. We're basically trying to find different ways to simplify.

If we have 0.4y=10 we can get y by itself by dividing 0.4 Ex: 0.4y/0.4 gets y alone. But what you do to one side, you must do to the other. So 0.4y/0.4 = 10/0.4

Answer 4

Does that make sense at all?

Answer 5

So B would be one of the answers?

Answer 6

That would be correct! So when we solve the equation 0.4y=10 we end up with y=10/0.4
y=25. Do you see any other equations that get the same answer?

Answer 7

A?

Answer 8

Well lets try it out. 0.4y = 10/0.4

This simplifies out to be 0.4y = 25

Then, divide 0.4 from y, and (what you do to one side you do to the other) So you're gonna end up with y= 24/0.4 which gives you y=62.5

Answer 9

So A is incorrect

Answer 10

Yes

Answer 11

It looks similar, so its kind of tricky

Answer 12

C is another correct answer. 10*2.5=25

Answer 13

Good job!!

0.4y x 2.5 = 10 x 2.5

0.4y/2.5 = 10 x2.5/2.5 (You do this to cancel it out)

So you're gonna end up with 0.4y = 10 which brings you back to your original equation :)

Answer 14

I believe A & C are the only correct answers. Am I correct?

Answer 15

Well remember we proved A to be wrong, because it actually equals 62.5 B and C are the correct ones haha

Answer 16

Sorry I meant B & C

Answer 17

If my question is answered and the only correct answers are B & C then I thank you for helping me with my question and I will reward you with a medal.

Answer 18

I believe those are the only correct ones! We proved A untrue, and D just seems to be all sorts of wrong. So no problem!

Answer 19

Thank you very much.