D is wrong. It’s an exponential function so every year the number of stores it opens grows. Which means there can’t be one number for each year in terms of amount of new stores.
I see 2 answers here. Company C and D at 8 months... (Companies A and B at 5 months)
Explanation:
I took the Maximum and subtracted it by the Minimum.
Ex. Company D: 27 (Max) - 19 (Min) = 8 months
R-9s=2 add 9s to both sides
r=2+9s making 3r-3s=-10 become:
3(2+9s)-3s=-10 perform indicated multiplication on left side
6+27s-3s=-10 combine like terms on left side
6+24s=-10 subtract 6 from both sides
24s=-16 divide both sides by 24
s=-16/24
s=-2/3, making r-9s=2 become:
r-9(-2/3)=2 perform indicated multiplication on left side
r+6=2 subtract 6 from both sides
r=-4
So s= -2/3 and r= -4