photo necessities produces camera cases. they have found that the cost c(x) of making x camera cases is a quadratic function in terms of x. a company discover that it cost 27 dollars to produce 2 camera cases, 105 dollars to produce 4 camera cases, and 675 dollars to produce 10 camera cases. find the total cost of producing 5 camera cases
when x=10, c(x)=675 675=a(10)²+b(10)+c 675=100a+10b+c
so we gots 27=4a+2b+c 105=16a+4b+c 675=100a+10b+c
eliminate c's from everybody multiply first equation by -1 and add to 2nd and 3rd equation the resulting 2nd and 3rd equations are shown below 78=12a+2b 648=96a+8b multiply top equation by -4 and add to bottom
-312=-48a-8b 648=96a+8b + 336=48a+0b
336=48a divide both sides by 48 7=a sub back
78=12a+2b 78=12(7)+2b 78=84+2b -6=2b -3=b sub back
27=4a+2b+c 27=4(7)+2(-3)+c 27=28-6+c 27=22+c 5=c
c(x)=7x²-3x+5 is da equation to produce 5 we do c(5)=7(5)²-3(5)+5 c(5)=7(25)-15+5 c(5)=175-10 c(5)=165