Answer:
The choice third ; a=9 , c= 18
Step-by-step explanation:


Answer:
5
Step-by-step explanation:
Answer: Mark has 28 marbles while Don has 85 marbles.
Step-by-step explanation:
Let x represent the number of marbles that Mark has.
Let y represent the number of marbles that Don has.
If Don has 1 more than 3 times the number of marbles Mark has, it means that
y = 3x + 1
The total number of marbles is 113. It means that
x + y = 113- - - - - - - - - - - - 1
Substituting y = 3x + 1 into equation 1, it becomes
x + 3x + 1 = 113
4x + 1 = 113
4x = 113 - 1 = 112
x = 112/4
x = 28
y = 3x + 1 = 3 × 28 + 1
y = 85
Check the picture below, so let's check the equations below hmmm
![\boxed{A}\\\\ y=\cfrac{16-3x}{4}\implies y=\cfrac{-3x+16}{4}\implies y = \cfrac{-3x}{4}+\cfrac{16}{4}\implies y=-\cfrac{3}{4}x\stackrel{\stackrel{b}{\downarrow }}{+4}~\hfill \bigotimes \\\\[-0.35em] ~\dotfill](https://tex.z-dn.net/?f=%5Cboxed%7BA%7D%5C%5C%5C%5C%20y%3D%5Ccfrac%7B16-3x%7D%7B4%7D%5Cimplies%20y%3D%5Ccfrac%7B-3x%2B16%7D%7B4%7D%5Cimplies%20y%20%3D%20%5Ccfrac%7B-3x%7D%7B4%7D%2B%5Ccfrac%7B16%7D%7B4%7D%5Cimplies%20y%3D-%5Ccfrac%7B3%7D%7B4%7Dx%5Cstackrel%7B%5Cstackrel%7Bb%7D%7B%5Cdownarrow%20%7D%7D%7B%2B4%7D~%5Chfill%20%5Cbigotimes%20%5C%5C%5C%5C%5B-0.35em%5D%20~%5Cdotfill)

Answer:
A.
Step-by-step explanation: