Tick (✓) the correct answer in each of the following:
(x+5)(x−3)=?
(a) x2+5x−15 (b) x2−3x−15 (c) x2+2x+15 (d) x2+2x−15
Find the roots of the following quadratic equations by the factorisation method. 25x2−x−35=0
5x3−15x2+25x by 5x