a2 + b2 + c2 - ab - bc - ca = 0
=> 2a2 + 2b2 + 2c2 - 2ab - 2bc - 2ca = 0
Rearranging,
a2 - 2ab + b2 + b2 - 2bc + c2 + c2 - 2ca + a2 = 0
=> (a2 - 2ab + b2) + (b2 - 2bc + c2) + (c2 - 2ca + a2) = 0
or (a - b)2 + (b - c)2 + (c - a)2 = 0
so a - b = 0, b - c = 0 and c - a = 0 (since each square is >=0)
that is, a = b = c
No. A times B = AB
associative property
C minus B equals AB
Equation, not expression. A and B are two numbers. (A + B)2 = A2 + B2 + 2(AB) ----------------------------------
An exothermic chemical reaction.
It is an expression and a term that are of equal value
144 Formula: c= (a2)+(ab)
(a3 + b3)/(a + b) = (a + b)*(a2 - ab + b2)/(a + b) = (a2 - ab + b2)
yes because ab plus bc is ac
2ab
Commutativity.
No. A times B = AB
The existence of the additive inverse (of ab).
associative property
the midpoint of AB.
C minus B equals AB
You cannot prove it since it is not true for a general quadrilateral.