Question

(5x-1)(5x+1)=(3+5x) prosze o obliczeni

Answer 1

(5x-1)(5x+1)=(3+5x)

(5x)² - 1² = 3+5x

25x² - 1 = 3+5x

25x² - 5x - 4 = 0

25x² - 5x - 4 = 0

ax² +  bx  + c = 0

a = 25   b = -5   c = -4

Δ = b² - 4 * a * c 

Δ = (-5)² - 4 * 25 * (-4) = 25 + 400 = 425

√Δ = √425 = √25 * 17  = √25 * √17 = 5√17

x₁ = (-b -√ Δ) : 2a

x₁ = (-(-5) -5√17) : 2*25

x₁ = (5 -5√17) : 50

x₁ = (1 -√17) : 10

x₂ = (-(-5) + 5√17) : 2* 25

x₂ = (5 + 5√17) : 50

x₂ = (1+ 1√17) : 10