You would multiply 15 ×8= 120 kids tried out
Math and english give you a total of 4 hours. and social studies and science gives you a total of 2 3/4 hours. add them up, and the closest he will spend to studying is 7 hours
For easier notation lets use: Nn=x and Nd=y
x+y=22
5x+10y=135
Multiply the first equation by 5 to get
5x+5y=110
Now you can eliminate x by subtracting the first equation from the second
5x+10y-5x-5y=135-110
5y=25
y=5
x=17
3pi+8(t-pi)-4t
=3pi+8t-8pi-4t
=-5pi+4t
