Question

find the values of y if y²+6y-25=0

Answer 1

use completing the square method

y^2+6y-25=0

y^2+6y=25

y^2+6y+9=34

(y+3)^2=34

y+3=root34

a root has both -ve and +ve sign,therefore there r 2 soln

y=4root2-3

and

y= -(4root2+3)