How do you solve the system of equations #20x - 16y = 28# and #10x - 8y = 14#?

1 Answer
Nov 22, 2016

The two equations are different forms of the same equation and therefore cannot be solved to give a final solution. There are infinitely many solutions.

Explanation:

If there are 2 variables in an equation, there in an infinite number of solutions. If a definite solution is to be found, two different equations are needed, which can then be solved as a system - other wise known as simultaneous equations.

in this case we have the equations :

#20x-16y = 28" and "10x-8y =14#

However it should be noted that the first equation is simply twice the second one.
In fact they can both be simplified to give the same equation.

#20x-16y = 28" "rarr div 4" " rarr 5x-4y=7#

#10x-8y =14" "rarr div 2" "rarr 5x-4y =7#

Therefore there are not two different equations and the given equations cannot be solved as a system, or as simultaneous equations.

There is an infinite number of solutions.

For any #x# value that is chosen, a corresponding #y# value can be found.

#x = 1 and y = -1/2#
#x=0 and y=-1 3/4#
#x= 1 2/5 and y= 0#
etc...