The parabolas defined by the equations y = x^2 + 4x + 6 and y = 2x^2 + 7x - 4 intersect at points and (a,b) and (c,d), where c >= a. What is c-a?
\(y = x^2 + 4x + 6 \qquad and \qquad y = 2x^2 + 7x - 4\)
These are both concave up parabolas
Looking of x values the points of intersection
\(x^2 + 4x + 6= 2x^2 + 7x - 4\)
solve that and you will get the 2 x values.
I will leave you to play with it now.