Question

Solve using matrices. Please show all work :)
3x + 5y = -4
x + 2y = -2

Answer 1

I can solve this using Cramer's Rule:
http://www.1728.org/cramer.htm

3x + 5y = -4
x + 2y = -2

Let a = 3 b=5 e=-4
c=1 d=2 f=-2

Denominator determinant dn = a•d -c•b
= 6 -5 = 1

x determinant = [e•d - f•b] / dn
= -4 • 2 - -2•5] / 1
= -8 +10
= 2

y determinant = [a•f -c•e]/1
= [3•-2 -1•-4]/1
= -6 +4
=-2