Question

2x(c+1)-x(x+5)=5(12-x)

Answer 1

2x(x+1) - x(x+5) = 5(12-x)
2x² + 2x - x² - 5x = 60 - 5x
x² + 2x - 60 = 0

Δ = b2 - 4.a.c 
Δ = 22 - 4 . 1 . -60 
Δ = 4 - 4. 1 . -60 
Δ = 244
Há 2 raízes reais.

x = (-b +- √Δ)/2a

x' = (-2 + √244)/2.1  
x'' = (-2 - √244)/2.1

x' = 13,620499351813308 / 2   
x'' = -17,620499351813308 / 2

x' = 6,810249675906654   
x'' = -8,810249675906654