The cost of making a dress is partly constant and partly varies with the amount of time it takes to make the dress if the dress takes 3hours to make it costs 2700 if it takes 5hours to make the dress it costs 3100 find the cost if it takes 1.5hrs to make the dress
c = mt+b
now, using the two facts they supplied, we have
3m+b = 2700
5m+b = 3100
subtract to find that
m=200, b=2100
making the final equation
c = 200t + 2100
so
c(1.5) = 300+2100 = 2400