For this case, the first thing we must do is define variables.
We have then:
x: number of pens
y: number of pencils
We now write the system of inequations:

The solution to the system of inequations is given by the shaded region.
Note: see attached image.
Answer: over the starting point
Step-by-step explanation:
X=7%
y=12%
x+y=20000
0.07x+0.12y=20000*0.19=3800
Answer: 2/20, because all those marbles in total is 100. the blue and black marbles would be 70, if you simplify all of it it'd be 2/25.
Step-by-step explanation: