Julia Pitre jdp8657
Week 11 Problem 7.1.2
url: http://people.tamu.edu/~jdp8657/homework.html
Problem: Use Kramer's rule to solve
x + y = a
rx + sy = b
for x and y with a,b,s, and r as parameters.
Solution:
Kramer's rule suggests that to solve an system of equations for a variable, one should take the determinant of the matrix, replacing the column of the variable that you want with the column of solutions, and divide that by the determinant of the matrix . When we apply that, we get:
det 
a 
1 


b 
s 
= x 
det 
1 
1 

r 
s 
det 
1 
a 


r 
b 
= y 
det 
1 
1 

r 
s 
x = (as  b)/(sr)
y = (b  ra)/(sr)