HELP ASAP PLEASE PLEASE HELP ME THESE ARE TWO Separate answers please help

Answer:
First one 5n-40 what does n so n= 8
The last one I see is d+15=30 so the d=15
Step-by-step explanation:
1. 5x8-40 i think
2.15+15=30 this is right am 91.1% right about this one