To begin, plug in a equation for a variable that is already isolated. There are two variables that are already isolated, and those are x and z. You could choose either to work with, doesn't matter, but I'm going to use x
So, plug the equation for x into another equation that has that same variable in it. Which would be:
.196x=10.4y
To begin, plug x equation into .196x=10.4y
.196(175+15y)=10.4y
Distribute .196 throughout the set of parenthesis
34.3+2.94y=10.4y
Begin to isolate y by subtracting 34.3 on both sides of the equation
2.94y=-23.9
Isolate y by dividing 2.94 on both sides of the equation
y=-8.13
Now, we have solved for one of the variables. The next thing to do is plug y into another equation that contains y in it. An easy one to use would be x=175+15y because x is already isolated
So, plug y=-8.13 into x=175+15y
x=175+15(-8.13)
Distribute 15 throughout the set of parenthesis
x=175-121.95
Subtract
x=53.05
And now we have solved for y and x. The only variable left is z
To solve for z, you have to plug y=-8.13 into the equation
z=10(-8.13)
Multiply
z=-81.3
x=53.05
y=-8.13
z=-81.3