11. The previous monthly balance on Barney Laurent's charge card is $144. 79. He made a payment of $144. 79 and had charges of $125. 22,

$23. 22, and $33. 65. There is no finance charge.

12. Amber Cho's monthly statement for her credit card shows a $529. 78

previous balance, her $85. 00 payment, a $7. 95 finance charge, and

credits of $49. 45 and $39. 22. This month's new purchases are $277. 32

and $38. 20.

13. Mario Azaria received the charge account statement partially shown

below. Find his (a) payments and credits, (b) new purchases, and

(c) new balance.

since both sides equal, there are infinitely many olutions.

x = -3

y = -18

step-by-step explanation:

to solve by substitution, substitute one variable and solve for the other. then substitute again to find the remaining variable.

x-1/3(3x-9) = -3 since y=3x-9 substittute y.

x-1/3(3x-9)=-3

x + x +3 = -3

2x+3=-3

2x+3-3= -3-3

2x=-6

x=-3

substitute again into y=3x-9

y=3(-3)-9

y=-9-9

y=-18

solution:

the given function is ,

      =

the three roots of this quadratic function is , 0 ,8 and 10.all the roots are real and rational.

if a quadratic equation is of the form ,

sum of the roots = a + b +c= 0+8+10=18=  

product of roots taken two at a time = a b + b c+ c a = 0+80+0=80 =  

product of roots = a b c = 0=  

there are 11 doors in a hall starting from 0 to 11.the entry in the hall is permitted through gate number 0 and exit is allowed through only gate number 8 and 10.so, three roots(0,8,10) of quadratic function is given by entry and exit route of this hall.