book Maths Puzzle Numerical Ability

I am supposed to solve this problem by completing the square:
(x squared) + 11x + 10=0

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book Other Question

PLEASE HELP ME TO SOLVE THIS PROBLEM IF YOU CAN EXPLAIN TO ME?
{X|X<-3}
I HAVE TO WRITE EACH SET IN INTERVAL ROTATION, AND GRAPH IT ON THE LINE. If f(x,y) = x+2y what is

a.f(3,5)
b.f(5,3)
c.f(a,b)
d.f(b,a)