Question 251450
55,000(1+x)^2=58,100
55,000(1+2x+x^2)=58,100
55,000+110,000x+55,000x^2=58,100
55,000x62+110,000+55,000-58,100=0
55,000x^2+110,000x-3,100=0
1,000(55x^2+110x-3.1)=0
{{{x = (-b +- sqrt( b^2-4*a*c ))/(2*a) }}}
x=(-110+-sqrt[110^2-4*55*-3.1])/2*55
x=(-110+-sqrt12,100+682])/110
x=(-110+-sqrt12,782)/110
x=(-110+-113.0575)/110
x=(-110+113.0575)/110
x=3.0575/110
x=.02779 or 2.779% is the interest rate.
Proof:
55,000(1+.02779)^2=58,100
55,000(1.02779)^2=58,100
55,000*1.05635=58,100
58,100~58,100