SOLUTION: Hi, this should be just about the last question I'm going to ask. It is a word problem: "Jacob attempted to solve for x in the equation 7(x+5)=3(x-8) using the steps below: Ste

Algebra ->  Equations -> SOLUTION: Hi, this should be just about the last question I'm going to ask. It is a word problem: "Jacob attempted to solve for x in the equation 7(x+5)=3(x-8) using the steps below: Ste      Log On


   



Question 374776: Hi, this should be just about the last question I'm going to ask. It is a word problem:
"Jacob attempted to solve for x in the equation 7(x+5)=3(x-8) using the steps below:
Step 1: 7x+35=3x-24
Step 2: 4x+35= -24
Step 3: 4x=11
Step 4: x=7"
Can you help me identify which is the first incorrect step? Thanks for the help!

Found 2 solutions by jim_thompson5910, mananth:
Answer by jim_thompson5910(35256) About Me  (Show Source):
You can put this solution on YOUR website!
Step 1: 7x+35=3x-24 .... this step is correct. Many students make a mistake distributing.


Step 2: 4x+35= -24 .... Two steps are done here, but it's still correct.


Step 3: 4x=11 ... When 35 is subtracted from both sides, the right side should be equal to -59 (since -24-35=-59). The student forgot that 35 was negative and said that 35-24=11). So this is where the mistake was made.


Step 4: x=7 .... and this is incorrect because step 3 is incorrect. The answer should be x=-59%2F4 instead of x=7


If you need more help, email me at jim_thompson5910@hotmail.com

Also, feel free to check out my tutoring website

Jim

Answer by mananth(16946) About Me  (Show Source):
You can put this solution on YOUR website!
7(x+5)=3(x-8) using the steps below:
Step 1: 7x+35=3x-24
Step 2: 4x+35= -24
Step 3: 4x=11
Step 4: x=7"
STEP 3 is incorrect
4x+35=-24
-35
4x+35-35=-24-35
4x=-59
/4
x=-59/4
...
m.ananth@hotmail.ca