How do you solve the following system: # 3x – 5y = 53 ,5x - 7y = 12 #?
Why on earth do they chose such awful numbers????
In solving equations for variable values the method is to manipulate so that you have a load of values and just one variable. It is then solvable. Variables in this case being
To make the -5y positive multiply everything by -1
Divide both sides by 5 ( this is the same as
It does not matter which of the 2 equations you use.
There are several methods for solving a system of equations, also known as simultaneous equations. The method you choose will depend on the format of the equations you are given.
- Elimination - [make additive inverses and add the equations]
- Substitution - [write one variable in terms of the other]
- Equating - [one variable is expressed in two different ways]
- Matrices - [ multiply a matrix by its inverse to get the unit matrix]
- Graphically - [ graph each equation and find the intersection]
In this example I will use the elimination method.
Now that you have value for
This was done by multiplying B by