Does anyone know how he got from step one to step two?

What is the multiple zero and multiplicity of f(x) = (x ? 3)(x ? 3)(x + 5)? multiple zero is 3; multiplicity is 2 multiple zero is 5; multiplicity is 1 multiple zero is ? 5; multiplicity is 1 multiple zero is ? 3; multiplicity is 2

The function show two sisters' savings account and the rate at which they plan to deposit money

Gabrielle's age is two times mikhail's age. the sum of their ages is 84. what is mikhail's age?