Question

fatore a expressao: 1-9y elevado a 2

Answer 1

(1)^2=1
(-9y)^2= 81y^2 
1+81Y^2

Answer 2

(1-9y)²
(1-9y).(1-9y)
1-9y-9y+81y
81y-18y=1
63y=1
y=1/63