7. solve 2x - y = 7 for y. then find the value of y when x = -1,0, and 1.

Step-by-step explanation:

We want to solve 2x - y = 7 for y.  Start by changing the signs of all terms, obtaining -2x + y = -7.  Now add 2x to both sides, obtaining  y = 2x - 7.

Now evaluate this at x = -1:             y(-1) = 2(-1) - 7 = -2 - 7 = -9

Now evaluate this at x = 0:             y(0) = 2(0) - 7 = 0 - 7 = -7

Now evaluate this at x = 1:             y(1) = 2(1) - 7  = 2 - 7 = -5

t= half of the arc subtended by t.

r= half of the arc subtended by r.  

t+r= half of the arc subtended by t + half of the arc subtended by r= half of 360=180

step-by-step explanation: