Answer: (x-1)(x+10) for part a,
x=1 and x=-10 for part b
Explanation:
To factor, we need to numbers that multiply to negative 10 and add to positive 9.
which are -1 and 10.
So x^2+9x-10=(x-1)(x+10)
For part b, for (x-1)(x+10)=0, we set each of the individual parts=0.
So x-1=0 makes x=1, and x+10=0 makes x=-10