Alrighty
remember

means

and

and

for all real values of x
so

means

means

which simplifies to
1=x²+4x-5
minus 1 both sides
0=x²+4x-6
use quadratic formula or complete the square

and

2 solutions
The answer is 832,719.
842,719 - 10,000 = 832,719
Set up a x/100 = (14-48)/48 = -34/48 Multiply the cross 48x = -3400 x = 70.8333 so around -70.83% change