What is the probability that a student who plays an instrument is in band

20/25

Step-by-step explanation:

Here, we want to calculate the probability that a student who plays an instrument is in band

The number of students who play instruments are;

25

Amongst this,

20 are in a band

So the probability of having a student who plays instrument and is in a band will be;

20/25 = 4/5

x = -3

y = -18

step-by-step explanation:

to solve by substitution, substitute one variable and solve for the other. then substitute again to find the remaining variable.

x-1/3(3x-9) = -3 since y=3x-9 substittute y.

x-1/3(3x-9)=-3

x + x +3 = -3

2x+3=-3

2x+3-3= -3-3

2x=-6

x=-3

substitute again into y=3x-9

y=3(-3)-9

y=-9-9

y=-18

answer: your answer is a