Answer:
(8,5)
Step-by-step explanation:
x=8
5*8-2y=30
40-2y=30 . subtract 40 from both sides
-2y=-10 . divide both sides by-2
y=5
for 2 points A(xa;ya) and B(xb;yb)
the slope is (yb - ya) / (xb - xa)
here
the slope = 4 = (17-r) / (4-(-1))
(17-r) / 5 = 4
17 - r = 20
r = 17 - 20
r = - 3
point (-1 ; -3)
That would be 7 - (-7) = 7 + 7 = 14 degrees F
+5 and -5 because you root 25 which gives you + 5 or - 5