Answer :
The first step is to state the equations that describe the given situations.
The first one says that she can put $300 away and save $30 every month. This, written as an expression is:
[tex]30x+300[/tex]Where x is the number of months.
For the second option she can put $100 away and save $50 every month. This, written as an expression is:
[tex]50x+100[/tex]Now, to find how many months would Tina save the same amount of money using either options make both expressions equal and solve for x:
[tex]\begin{gathered} 30x+300=50x+100 \\ 30x-50x=100-300 \\ -20x=-200 \\ x=\frac{-200}{-20} \\ x=10 \end{gathered}[/tex]After 10 months she would have the same amount using either options.
To find how miuch would she save, use one of the expressions, any of them, and replace x for 10, for example, let's use the first expression:
[tex]30(10)+300=600[/tex]She will save $600 using either option.