Question

3) Calcule os produtos:
a) (x + 9) (X - 9) =
b) (a + b). (a - b) =
c) (X - 6). (x - 6) =
d) (y + 3). (y +3) =​

Answer 1

Ola

a)

X^2 -9x +9x-81=

X^2 -81=0

X^2 =81

X=√81

X=9

b)(a+b)(a-b)

a^2 -ab+ ab - b^2

a^2 -b^2

c)(x-6)(x-6)

X^2 -6x -6x -36

X^2 -12x =36

a=1 b=-12 c=36

∆=(-12)-4.1.36

∆=144 -144

∆=0

d)(y+3)(y+3)

y^2 +3y +3y +3^2=0

y^2 +9y +3^2 =0

y^2 +3^2 =9y

3y^2=9y

3y=√9

3y=3

y=3/3

y=1