Question

Can someone please solve this and tell me how by explaining? Please help me figure this out, I am completely lost. Thanks in advance :)

https://media.glynlyon.com/g_alg01_2013/8/2a132.gif

Answer 1

just remember (a-b)(a+b)=a^2-b^2

Answer 2

make sure you understand that ,multiply that out

Answer 3

after you done that match a and be with the values at your problem

Answer 4

Oh, ok :) Thank you soooo much :)

Answer 5

@eldi https://media.glynlyon.com/g_alg01_2013/8/2a124.gif what would this one be? \[? + 2\sqrt{5}\]