C=15x+150 r=45x liner equations by graphing

Can someone me with #s 8, 9, and 11. with just one of the three also works. prove using only trig identities.

The ivring berlin learning center would like a possible net profit of $650,000 on its new resource manual it sells to schools. the fixed costs for producing the manual are $780,000 and the variable cost per package is $19.85. if the estimated unit sales are 1,250,000 units, what selling price unit should the ivring berlin learning center try?

Car a and car b were in a race .the driver of car b claimed that his car was twice as fast as car a