How do you solve 3u + z = 15 and u + 2z = 10?
1 Answer
Sep 7, 2015
Explanation:
Your system of equations looks like this
#{(3u+z = 15), (u + 2z = 10):}#
Multiply the first equation by
#{(3u+z = 15 | * (-2)), (u + 2z = 10):}#
#{(-6u-2z = -30), (u + 2z = 10):}#
Add these two equations to get one equation with one unknown,
#-6u - color(red)(cancel(color(black)(2z))) + u + color(red)(cancel(color(black)(2z))) = -30 + 10#
#-5u = -20 implies u = ((-20))/((-5)) = color(green)(4)#
Now use this value of
#4 + 2z = 10#
#2x = 6 implies z = 6/2 = color(green)(3)#