5(90 = x + z)450 = 5x + 5zThese are now my two equations:270 = 5x + 2.75z450 = 5x + 5zI can ELIMINATE the xs by subtracting the two equations (because 5x - 5x = 0).-180 = -2.25zSolve for z.z = 80Now I can find x. Just insert the value of z into any of your equations.......
z=80
Substitute z in any of the equation
x+z=90
x+ 80=90
x=10
Yes, those are your two equations.
You can use either substitution or elimination. I would personally use substitution, but if you want to do elimination:
In Elimination you want the coefficients of either the x's or z's to be equal (if you're going to subtract the two equations) or opposite (if you're going to add the two equations.) Doesn't really matter; choose either or.
I've decided to make the coefficients of the x's equal. To do that, I'll multiply the entire second equation by 5.
5(90 = x + z)
450 = 5x + 5z
These are now my two equations:
270 = 5x + 2.75z
450 = 5x + 5z
I can ELIMINATE the x's by subtracting the two equations (because 5x - 5x = 0).
-180 = -2.25z
Solve for z.
z = 80
Now I can find x. Just insert the value of z into any of your equations.
90 = x + z
90 = x + 80
x = 10
z = 80
x = 10
