andrew is having a irrigation system installed in his yard company a charges 1250.00 plus 15.00 per sprinkler head company b charges 1200.00 plus 17.00 per spinkler head how many spinkler heads will andrew need to have to make company a a better deal

Question

anonymous · Answer

$$y=15x+1250$$$$y=17x+1200$$Solve simultaneously for x, anything below this value and company b will be cheaper.

anonymous · Answer

let X be the number of sprinkler heads. with company A, his total cost is 
1250+15X
with company B his total cost is 1200+17X
to get a better deal from company A, cost of company A is less than cost of company B
1250+15X<1200+17X
X>25

anonymous · Answer

anything greater than 25 sprinklers and he gets a better deal from company A

anonymous · Answer

bah i read it right the first time has to be mre than 25 at 25 they are equal in costs

anonymous · Answer

i don't understand how you got your answer

anonymous · Answer

Think about a graph of cost against time. The two functions you'd plot are y=15x+1250 and y=17x=1200, where y is the cost and x is the amount of sprinkler heads. The point at which these lines meet is the point at which the cost for either is the same. Below this, the line with the shallower slope will have a higher cost and above this the line with the steeper slope will have a higher cost.