Answer:
m = E/c²
Step-by-step explanation:
E = mc²
mc² = E
Divide both sides by c².
-4x+y = -5
Y+7=4(x-3)
Y+7=4x-12
+7. +7
Y=4x-5
-4x+y=-5
attached below
They must sell 43 tickets to raise $500
Cost to book the venue = $145
-145 plus 500 (money they need to raise) = $645
Each ticket costs $15
645/15 = 43 tickets
c not sure tho
