Answer:
A and C
Explanation:
20) Since the triangles are similar, you can say that 98 corresponds to 42 and 77 corresponds to 3x+6, because of this you can write an equation ((98/77)(3x-6) =42) and then simplify to get x = 13.
21) Since ABC and DFE are similar, we can say that 2x+2 corresponds to x+3 and 24 corresponds to 16. You can write this as the equation (24/2x+2)(x+3) = 16 and simplify to get x=5.
I hope this helps :)