MR-569 / 569. problem

Solve the equation below:

x2-2x-35=0

x2-2x-35=0

a=1; b=-2; c=-35;

x1,2=-b±b2-4ac2a

x1,2=--2±-22-4·1·-352·1

=2±4+1402

=2±1442

=2±122

x1=2+122

x1=142

x1=7

x2=2-122

x2=-102

x2=-5