Answer:
1. He added 5 instead of subtracted 5.
2. He should have subtracted 5.
3. 2 2/3
Step-by-step explanation:
3x+5=13
subtract 5 to both sides 3x=8
divide both sides by 3 x=8/3 or 2 2/3
Answer:
.
Step-by-step explanation:
We want to convert the function into the form that let's us easily find the x-intercept, and it would be for the form
because then we can find the x-intercept in the following manner:



We factor our function
and get

Now this form let's us easily find the x-intercepts:


and so we pick the second choice: f(x)=(2x+1)(2x-1).