A(n)=a+(n-1)d
A(40)= -1+(40-1)-4
A(40)= -1+39(-4)
A(40)= -1+(-156)
A(40)= -157
Dress: 93$ at 100-25%=75%
-> divide the marked down cost by the percentage to get the cost of a single percent and then multiply it with the markdown again to get the saved cost
93/75*25=93/3*1=31*1=31$
shoes 119$ at 100-15%=85%
119/85*15=119/17*3=7*3=21
add both savings together for the full sum: 31+21=52$
Answer:
153 pounds
Step-by-step explanation:
Just subtract 250 from 403