Question

Jennifer owes $13,000 to a friend who is charging her interest of 0.90% p.m. She is required to settle the amount owed with two equal payments, one today and the other in three months. Calculate the size of the payments using three months as the focal date.
I am totally lost - I cannot follow the steps of the answer given "S1+xP1(1+rt1)+xx(1+0.009×3)+x1.027x+x2.027xx=S2=P2(1+rt2)=13,000(1+0.009×3)=13,351=13,351=13,3512.027=$6,586.58"

Answer 1

I have no idea what your equation is supposed to say or do.
Since you are talking about a "focal date", I will assume you have learned to make a time line.

label it "now" or 0, 1,2,3 months
I place the debt above the line , and the payments below the line, so

write 13,000 at 'now' above the line
write x at 'now' and x at 3 months
Using 3 months as the focal date:
x(1.009)^3 + x = 13,000(1.009)^3
x( 1.009^3 + 1) = 13000(1.009^3
x = 13000(1.009)^3 /(1.009^3 + 1) = $6587.35

personally , I would have picked 'now' as the focal date
x + x(1.009)^-3 = 13000
x = 13000/(1.009^-3 + 1) = 6587.35