A regular polygon has 10 sides. Calculate how many right angles are equal to the
Sum of its interior angles.​

First subtract 10 from both side
y^2+6y-16=0
(y+8)(y-2)=0
-8 and 2

It's like discovering the answer to a puzzle. the purpose in solving an equation is to find the value or values of the variable that makes it a true statement. any value of the variable that makes the equation true is called a solution to the equation.