I'm stuck, what steps would I use

Okay,
so it would be like
3d-2.75=1.5
-2.75+3d=1.5
-2.75+2.75+3d=1.5+2.75
3d=1.5+2.75
3d=4.25
4.25/3=1.5?
d=1.5
Did I do that right?
And I have one more that I don't know how to start if you don't mind... (or someone else)
2m+1/3 = 3m-2/5
 
Oh jeez I'm sorry, I got help from somewhere else and then for some reason replied with those steps instead.
Is it incorrect though...? I'm suppose to show how to get it using left side equals right side.
 
sarahilc said:
Yes, your result d = 1.5 is incorrect because you did not properly divide 4.25 by 3.

:idea: You could have determined for yourself that 1.5 is not a solution for d, by checking that value in the original equation (always a good idea).

I mean, let d = 1.5, and evaluate each side of the original equation, to see if you get a true statement.

3(1.5) - 11/4 = 3/2

This simplifies to 1.75 = 1.5, which is clearly false, so d = 1.5 is not correct.

(The correct solution for d will cause the original equation to evaluate to 1.5 = 1.5, when you check.)

Your work looks okay, until the end, where you made an arithmetic mistake.

Denis showed you an easier way (i.e., less steps); however, since you typed out your work, I'll comment on it, instead.


3d-2.75=1.5

-2.75+3d=1.5 This step is okay. (With more practice, you won't need it.)

-2.75+2.75+3d=1.5+2.75

3d=1.5+2.75

3d=4.25

4.25/3=1.5? Why did you insert this line, and what happened to symbol d?

Are you actually trying to ask us whether or not 4.25/3 equals 1.5?

You could easily answer that question yourself by using a calculator, yes?

Let's go back the the last correct line:

3d = 4.25

The next step is to divide both sides by 3 (you did not show this step)

3d/3 = 4.25/3

Simplify the lefthand side (the 3s cancel)

d = 4.25/3

Use a calculator to simplify this expression for d, if your teacher expects you to report a decimal approximation for d versus the exact value.

(If your teacher expects the exact solution, then you'll need to learn how to do arithmetic with fractions.)


And I have one more that I don't know how to start if you don't mind...

We don't mind how many questions you post, but please start a new thread for each new exercise. 8-)

Click to expand...
 
You must log in or register to reply here.
Top