Question

Simplifique as expressões a seguir.
(x - 3)² - (x + 2)² + (x + 3)(x - 1)

Answer 1

(x²-2.x.3+3²) - (x²+2.x.2+2²)+x²-x+3x-3=

x²-6x+9-x²-4x-4+x²+2x-3= 
(anula x² e -x²) 
(-6x-4x+2x=-8x)
(9-4-3)
x² -8x+2=0
Δ=b²-4ac
Δ=(-8)²-4.1.2
Δ=64-8
Δ=56     √Δ=√56≡7,5
x'=8+7,5/2
x'=7,75
x''= -b-√Δ/2a
x''= 8-7,5/2
x''=0,25
s= 0,25 e 7,75