Respuesta :
r = number of red pens
b = number of blue pens
If we have 36 workers and each worker requires a pen, we need 36 pens.
36 = r + b
3r = b (For every 3 red there are 9 blue. So there are 3 times as many blue as red)
Now, substitute 3r = b into the first equation.
36 = r + b = r + 3r = 4r
36 = 4r
9 = r
Therefore, we need 9 red pens. Plug this back into our 3r=b equation to solve for b.
3r = b
3(9) = b
27 = b
Therefore, we need 27 blue pens.
b = number of blue pens
If we have 36 workers and each worker requires a pen, we need 36 pens.
36 = r + b
3r = b (For every 3 red there are 9 blue. So there are 3 times as many blue as red)
Now, substitute 3r = b into the first equation.
36 = r + b = r + 3r = 4r
36 = 4r
9 = r
Therefore, we need 9 red pens. Plug this back into our 3r=b equation to solve for b.
3r = b
3(9) = b
27 = b
Therefore, we need 27 blue pens.