How do you solve #5x + 3y = -4.5# and #2x + 1.2y = -1.8# using matrices?

1 Answer
Nov 4, 2017

Answer:

no solution, the lines are parallel .

Explanation:

#5x+3y=-4.5--(1)#

#2x+1.2y=-1.8--(2)#

in matrix form

#((5,3),(2,1.2))((x),(y))=((-4.5),(-1.8))#

to use matrices we need the inverse of the #2xx2# matrix

to do this we need its determinant so we will do this first

#Delta=|(5,3),(2,1.2)|#

#=5xx1.2-2xx3#

#=6-6=0#

#Delta=0:.#the inverse does not exist, so there are no solutions to the equations.

In fact eqn#(1)=2.5xx#eqn#(2)# which means they are parallel lines and do not intersect