Why was the music teacher not able to open his class room?

In what book/story gotta tell us this if you want the question answered

Step-by-step explanation:

Because his keys were  on the piano.

Step-by-step explanation:

You get the idea.

options a,b,c are the right answer.

step-by-step explanation:

a linear parent function is always represented as y = x

if we write this function in the form of y=mx+c

⇒

or  

now if we plot a graph we will find these characteristics:

1) y intercept of the graph is zero so its a straight line passing through origin.

2) as we can see in both the forms of function written, values of x and y may be either positive or negative for the positive slope means points on the graph are either in first quadrant or in third one.

3) it's slope is one.

1/2*qr*rs

step-by-step explanation: