What does it mean to solve a system of equations?

Question

 I need help with this because i missed school and got homework but I do not know what to do.

Answer 1

A system of equations is when you have two or more equations and you try to solve two or more unknowns. You must have as many independent equations as you have unknowns. There are several ways to solve, and since they just introduced it, you're probably only going to need the easiest one.

 

5x + 2y = 40

x + y = 100

 

These are independent because the second is not just a multiple of the first. To solve, express y in terms of x

 

y = 100 - x

 

Now plug that definition of y into equation 1.

 

5x + 2(100 - x) = 40

 

5x + 200 - 2x = 40

 

3x = -160

 

x = -160/3

(y is now easy to find.)

 

There should be plenty of support materials on solving systems of equations here and other math resources. Post back when you have a question about a specific problem! Hope that helps!

P.S. Always check your work by plugging your answers back into the equations and make sure both work. And don't forget to find all unknowns. Don't just stop when you find x.