22. Step by step: 2x^2+5x-3=0
factor the left side
(2x-1)(x+3)=0
set the factors to equal zero
2x-1=0 and x+3=0
x=1/2 x=-3
23. Use same technique.
3x^2-13x-10=0
factor the left side once more
(3x+2)(x-5)=0
set factors to zero
3x+2=0 and x-5=0
x=-2/3 x=5
