Answer:
4
Step-by-step explanation:
C makes it true always true.
Answer: r=7x-1/8
2(4r+3)=7x/2+5/2
4r+3=7x+5/2
4r+3-3=7x+5/2 -3
4r=7x+5/2 -3
4r/4= 7x-5/2/4 -3/4
r=7x-1/8
750
465
+ 285
equals 750