Answer:
[tex]\boxed{ \text{B. 10 weeks, \$310 }}\\[/tex]
Step-by-step explanation:
We have two conditions:
[tex]\begin{array}{lrcll}(1) & y & = & 25x + 60 & \\(2) & y & = & 30x + 10 & \\ & 25x + 60 & = & 30 x + 10 & \text {Set (1) = (2)} \\ & 50 & = & 5x & \text{Subtracted 25x from each side} \\& x & = & 10 &\text{Divided each side by 5} \\\end{array}\\$ $\\\boxed{ \textbf{The number of weeks is }x = 10}\\[/tex]
Bella: y = 25x + 60 = 25(10) + 60 = 250 + 60 = 310
Heather: y = 30x + 10 = 30(10) + 10 = 300 + 10 = 310