Please solve these. I'm not sure which diagram to use though.

Which value of c would make he following expression completely factored? 8x+cy

Rose bought a new hat when she was on vacation. the following formula describes the percent sales tax rose paid b=t-c/c

22. catie is starting a babysitting business. she spent $26 to make signs to advertise. she charges an initial fee of $5 and then $3 for each hour of service. write and solve an inequality to find the number of hours she will have to babysit to make a profit. interpret the solution.!