Answer:
a = -10
Step-by-step explanation:
You would do 0.25x (x is the unknown total number)=19. It is because of is a multiply sign, so 0.25*x=19. Divide both sides by 0.25 and you get 76 as your answer.
Answer:
x = 19, y = -5
Step-by-step explanation:
x + y = 14 => x= 14-y
2x + 4y = 18 => 2(x+2y)=18 => x+2y=9
x+2y=9 => (14 - y) + 2y = 9
14 + y = 9 => y = -5
x + (-5) = 14 => x=19
The angle does not matter. Think of it as finding the other side to a triangle. Use

a=39 (line AB)
b=b (the leg we need to find)
c=89 (line BD)


(subtract the 1521 from both sides)

(square root both sides)

b = 80
AD=80
44 pounds
gonna type so i can post this because of the 20 character limit :P