Question

efectue e simplifique (2x + 1) ²-(3x + 2 )²

Answer 1

(2x + 1)² - (3x + 2)²
(2x + 1)*(2x + 1) - (3x + 2)*(3x + 2)
(4x² + 2x + 2x + 1²) - (9x² + 6x + 6x + 4)
(4x² + 4x + 1) - (9x² + 12x + 4)
4x² + 4x + 1 - 9x² - 12x - 4
- 5x² - 8x - 3 = 0

Δ = b² - 4ac
Δ = (-8)² - 4(-5)(-3)
Δ = 64 - 60
Δ = 4
√Δ = 2

x1 = - b + 2 / 2a
x1 = [-(-8) + 2] / 2(-5)
x1 = (8 + 2)/ -10
x1 = - 10/10
x1 = -1

x2 = - b - 2 / 2(-5)
x2 = 8 - 2 / -10
x2 = - 6/10
x2 = - 0,6

Qualquer dúvida, só perguntar!

Answer 2

(2x+1)²-(3x+2)²
2x²+2.2x.1+1²-(3x+2).(3x+2)
4x²+4x+1-(9x²+6x+6x+4)
4x²+4x+1-(9x²+12x+4)
4x²+4x+1-9x²-12x-4
4x²-9x²+4x-12x+1-4
-5x²-8x-3=0
∆=b²-4ac
∆=(-8)²-4.(-5).(-3)
∆=64-60
∆=4
x=-b±√∆/2a
x=-(-8)-2/2.(-5)
x=8-2/-10
x=6/-10
x=-0,6
x=-(-8)+2/2.(-5)
x=8+2/-10
x=10/-10
x=-1
S={(-0,6 ; -1)}