Answer:
The below explanation can give you whatever you are seeking.
Step-by-step explanation:
The two unknowns in the equation are "n" and "d"
$78.90 = n(.05)+d(.10) ........................ (1)
Make both unknowns the subject of the formula and substitute for each other
[tex]n = \frac{78.90 - d(.10)}{.05}[/tex] ............................ (2)
also
[tex]d = \frac{78.90 - n(.05)}{.10}[/tex] ............................ (3)
You can substitute for either "n" or "d" in equation (1),
Putting equation (3) into (1)
78.90 = n(.05) + [tex][\frac{78.90 - n(.05)}{.10}] .10[/tex]
78.90 = n(.05) + 78.90 - n( .05)
collecting all like terms
78.90 - 78.90 = n(.05) - n(.05)
0 = n(.05 - .05)
0/0 = n
n is undefined
Putting equation (2) into (1)
78.90 = [tex][\frac{78.90 - d(.10)}{.05}] .05[/tex] + d(.10)
78.90 = 78.90 - d(.10) + d(.10)
78.90 - 78.90 = - d(.10) + d(.10)
0 = d (-.10 + .10)
0/0 = d
d is also undefined