Question 190630
If the expression {{{x^2+bx+c}}} is a perfect square, then {{{c=(b/2)^2}}} (ie take half of b and square it to get c)



So in this case, {{{b=-10}}}. So {{{d=(-10/2)^2=(-5)^2=25}}} which means that {{{d=25}}}. So the perfect square is {{{y^2-10y+25}}}