Urgent ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ is the fourth question of P92 in the second volume of Senior One, and now I need an answer. Please help me, idiot.
1.(a+b)=4
Both sides are squares, and you will get:
Answer? +b？ +2ab= 16
=a？ +b？ +2x5/2= 16
So a? +b？ =9
2. (A-B)? =a？ +b？ +2ab-4ab=9-5=4