A^2 + b^2 + c^2 - ab - bc - ca = 0
a.a + b.b + c.c = a.b + b.c + c.a
equating term by term:-
a = b
b = c
c = a
Therefore a = b = c
29,032,000,000 is the standard form
Soo 100.26-15% off = $85.25 and 59.99 you need to crank it up 1 so $60-10% off=$54 last add $85.25+$54=$129.25
So no she is not right
