Alaina was asked whether the following equation is an identity: (2x + 1)2 – (x + 1)2 = 3(x + 1)2 - 1
She performed the following steps:
(2x + 1)2 – (x + 1)2
Step 1
= 4x2 + 4x +1 - 2 + 2.0 + 1
Step 2
= 3x2 + 6x + 2
Step 3
→
= 3x² + 6x +3-1
Step
= 3(x2 + 2x + 1) - 1
Step 5
3(x + 1)2 – 1
For this reason, Alaina stated that the equation is a true identity.
Is Alaina correct? If not, in which step did she make a mistake?

yerror she made is at the level of the first step if you want me to show it to you ask me in comment

made a step 1 mistake

Step-by-step explanation:

the step is incorrect because the expansion of (x+1)^2 is x^2+2x+1. But since there’s a minus sign before it , all plus signs should be changed to minus.

she played for 18.75 hours.

step-by-step explanation:

if she played 2/4 of a hour on tuesday. and there is 60 minutes in an hour and 60 divided by 4 is 7.5. and she played 2/4 of an hour on thursday then again 60 divided by 4 is 7.5, you add 7.5+7.5=56.25. now you have to do 1/4 of an hour, it equals 3.75. now you have to add them all up. 3.75+7.5+7.5=18.75

i hope this and i hope you get it right. it took me a while to get this done for you. : )

a

b

d

step-by-step explanation: