Part A
means that what she spends must be less than what she must earn
![90+2.50C<3.75C](https://img.qammunity.org/2023/formulas/mathematics/college/9znjbzmvtqu28r0g55vfdqfibi1l9u6hoi.png)
where C is the number of cards
solving the inequality...
![\begin{gathered} 90+2.50C<3.75C \\ 90<(3.75-2.50)C \\ 90<1.25C \\ (90)/(1.25)72 \end{gathered}](https://img.qammunity.org/2023/formulas/mathematics/college/ekt4r4vrvmemdo49ie0r5r4695l0cfmfxw.png)
she should make more than 72 Cards ,at least 73
Part B
If she must make 73 to earn something and Susana already made 8 we must do a subtraction to find out how many are missing
so
![73-8=65](https://img.qammunity.org/2023/formulas/mathematics/college/6hgwepk3tqm95v4kjkdyv93fvawqx9bci0.png)
she must make and sell 65 cards to make a profit