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Solving Equations for Variables

I need to solve the following for the 2 variables and plot on a grid line. This is for a linear programming model and I can not figure out the algebra. Can do it in solver, but not on paper and I need all work shown.

42x + 30Y = 180

3 C + 8 B = 20

Please show all work.

Solution Preview

42X + 30Y = 180
Solve for x
Get the X term alone: 42X = 180 - 30Y
Get the X alone: X = (180 - 30Y)÷42
Solve for y
Get the y term alone: 30Y = 180 - 42x
Get the y alone: y = (180 - 42x)÷30

3c + 8b = 20
Solve for c
Get the c term alone: 3c = 20 - 8b
Get the c alone: c = ...

Solution Summary

This shows two examples of how to solve two-variable equations for each variable, and how to choose points to plot graphs.