Tìm x biết (x + 1) * (x + 3) + (x - 2) * (4 + x) = 0

To solve this equation, we first need to expand and simplify the expression:

(x+1)*(x+3) + (x-2)*(4+x)
= x^2 + 3x + x + 3 + 4x - 8 - 2x
= x^2 + 4x + 3 + 4x - 8 - 2x
= x^2 + 6x - 5

Now, we set the expression equal to 0 and solve for x:

x^2 + 6x - 5 = 0

This is a quadratic equation that can be factored or solved using the quadratic formula. Factoring, we get:

(x + 5)(x - 1) = 0

Setting each factor equal to 0, we find the solutions for x:

x + 5 = 0
x = -5

x - 1 = 0
x = 1

Therefore, the solutions to the equation are x = -5 and x = 1.