Subtract and answer with the simplest form

−338−78 = ?

thank you

Find the length of the following tangent segments to the circles centered at o and o' whose radii are 5 and 3 respectively and the distance between o and o' is 12. what is the tangent segment of cd?

Icould really use some with this question.

Rewrite the following quadratic functions in intercept or factored form. show your work. y = x^2 + 7x + 10