0.7y+2.1r-2100=0.2y-2r-140

Question

Find for y and r

Answer 1

Group variable terms together:

First the y's: (0.7-0.2)y=0.5y,

Then the r's: (2.1+2)r=4.1r,

Then the constants: -2100+140=-1960.

So the equation becomes 0.5y+4.1r-1960=0 which can be arranged in different ways, e.g., y=3920-8.2r.

There's only one equation so there are many solutions for y and r, but the equation shows the relationship between y and r which can be graphed: