Respuesta :

Step-by-step explanation:

a²-20a+36=0

a²-(18+2)a+36=0

a²-18a-2a+36=0

a(a-18)-2(a-18)=0

(a-18)(a-2)=0

either,. or,

a-18=0. a-2=0

a=18 a=2

the value of a is 18 or 2