I know this is not an answer but, I love your handwriting!
It is soooo much neater than mine!
- Laura <3
R=-4
desmos is a good app to check out these priblems (i do it all the time)
“what is the sum of the angles of a triangle” 180 degrees
Answer:
28
Step-by-step explanation:
a+b+c=9 and a2+b2+c2=35 then by using identity
(a+b+c)2=a2+b2+c2+2ab+2bc+2ca,we get the answer 9x9=35+2(ab+bc+ca)
2(ab+bc+ca)=9x9-35
2(ab+bc+ca) =81-35then we get ab+bc+ca=46/2 so ab+bc+ca=23
