Question

como desenvolver os produtos (y+9).(y+3)

Answer 1

(y+9).(y+3)
= y.y + 9.3
= y² + 27

Answer 2

(y+9)*(y+3)=
y*y+y*3+9*y+27=
y²+3y+9y+27=
y²+12y+27=

a=1  b=12  c=27

Δ=b²-4ac
Δ=12²-4*1*27
Δ=144-4*27
Δ=144-108
Δ=36

x= -b+-√Δ/2a
x= -12+-√36/2*1
x= -12+-6/2
x'= -12+6/2
x'= -6/2
x'= -3
x''= -12-6/2
x''= -18/2
x''= -9