Answer:
x=2
Explanation:
We will use the secant-secant Formula:
(whole secant) x (external part) = (whole secant) x (external part)
(1+x+4) * (x+4) = (11+x+1) * (x+1)
Combine like terms
(x+5) (x+4) = (x+12) (x+1)
FOIL
x^2 + 4x+5x + 20 = x^2 + x+ 12x + 12
Combine like terms
x^2 + 9 x + 20 = x^2 + 13 x + 12
Bring everything to the left
x^2 + 9 x + 20- (x^2 + 13 x + 12) = x^2 + 13 x + 12-( x^2 + 13 x + 12)
x^2 + 9 x + 20- (x^2 + 13 x + 12) =0
Distribute the minus sign
x^2 + 9 x + 20- x^2 - 13 x - 12 =0
Combine like terms
-4x +8 = 0
Subtract 8 from each side
-4x+8-8=0-8
-4x=-8
Divide each side by -4
-4x/-4 = -8/-4
x=2