Basic order of operations question: ab^2 - d

Yes, you are correct. The value of \(\displaystyle ab^2- d\), with a= 3/4, b= -8, and d= 3 is
\(\displaystyle (3/4)(-8)^2- 3= (3/4)(64)- 3=3(16)- 3= 48- 3= 45\), not 33 as is given there.
 
Sorry for asking another question in the same thread, but I didn't feel this warranted a new thread:

I'm not sure but I think this one is wrong too? http://www.slader.com/textbook/9780078908620-algebra-2-homework-practice-workbook/8/practice/22/

I mean, how can W = -38? For that to be the case, the absolute value on the left would have to be negative, which is by definition not possible. My solution to this was W = -4. Am I making a calculation error or are there just a lot of mistakes on that website?

My calculation was as follows:

|4w - 1| = 5w + 37
4w - 1 = - 5w - 37
9w - 1 = - 37
9w = -36
w = -4

For the other solution:

|4w - 1| = 5w + 37
4w - 1 = 5w + 37
-1 = w + 37
w = -38

This second one is the solution arrived at in the link above. But if we substitute w for -38 in our original equation, we get:

|4(-38) - 1| = 5(-38) + 37
|-152 - 1| = -190 + 37
|-153| = -153
153 = -153

Which is obvoiusly not the case. Or am I missing something in how these equations are supposed to be solved?
 
Last edited:
syncmaster913n said:
Sorry for asking another question in the same thread, but I didn't feel this warranted a new thread:

I'm not sure but I think this one is wrong too? http://www.slader.com/textbook/9780078908620-algebra-2-homework-practice-workbook/8/practice/22/

I mean, how can W = -38? For that to be the case, the absolute value on the left would have to be negative, which is by definition not possible. My solution to this was W = -4. Am I making a calculation error or are there just a lot of mistakes on that website?
Click to expand...
You are correct → w = -4
 
syncmaster913n,

I went to that site, created an account, posted my solution for the first problem, your solution
at the other page, and sent that incorrect problem solver two private messages.

The second private message is:

You [meaning incorrect problem solver at site below] almost completely fouled up the workings of this
absolute value equation. The answer you gave should have been thrown out, and the correct answer
was never given by you. I recommend that you not work out any more solutions for students to absolute
value equations until you can review them further.

This was for the problem here:
http://www.slader.com/textbook/9780078908620-algebra-2-homework-practice-workbook/8/practice/22/#
 
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