AB would equal 3.57 or 3.6 rounded as your directions ask because the sides are supposed to be proportional. When you do 21/5, you get 4.2. Then, you can just do 15/4.2 and get 3.57.
Answer:
3.25
Step-by-step explanation:
2 + d = 2 - 3 (d - 5) -2
d= -3d+15-2
4d=13
d= 13/4= 3.25
Solve for y:
3x = 7y + 21
~Subtract 7y to both sides
3x - 7y = 21
~Subtract 3x to both sides
-7y = 21 - 3x
~Divide -7 to both sides
y = -3 + 3/7x
~Change order
y = 3/7x - 3
Best of Luck!