Penerapan aljabar dalam kehidupan sehari-hari

1.      A mother every month gets a salary of Rp 1.500.000,00. He was given additional money from her husband Rp 500,000.00 per month. It takes Rp 200,000.00 for spending money per month. Total tuition fees from the 2nd son of Rp 1,000,000.00. Mother confused, how much money individual pocket should he give for his two children per week, but money per month remaining Rp 200,000.00 for savings.

Answer :

We consider each child's pocket money per week as x

(1.500.000 + 500.000) - 200.000        = 1.000.000 + 200.000 + (4 X 2x)

2.000.000 - 200.000                            = 1.200.000 + (8x)

1.800.000                                            = 1.200.000 + 8x

1.800.000 - 1.200.000                         = 8x

600.000                                               = 8x

x                                                          =

x                                                          = 75.000

Why (4 x 2x) because 1 month = 4 weeks and it is an allowance 2 x 2 children.
Thus, each child allowance within a week is Rp 75,000.00.

2.      Suppose our pocket money amounting to Rp 50,000.00 each week. Because every Tuesday and Friday we are les at 14:20 pm after school while we do not go home first (canal sampa les) then we need money to eat + allowance of Rp 9000.00. Well, we are confused determine allowance every day other than Tuesday and Friday for two weeks in two weeks if we want to save the money of Rp 50,000.00. With the help of algebra we can define our pocket money per day.

Answer :

We consider our pocket money per day (other than Tuesday and Friday because the existing quota, ie 9000.00) with x. Then,

100,000                       = (allowance 2 weeks)

50,000                         = (money saving for 2 weeks)

100.000 - 50.000         = (4 x 9.000)  + 2(6x - 2x)

50.000                         = 36.000 + 2(4x)

50.000                         = 36.000 + 8x

50.000 - 36.000           = 8x

14.000                         = 8x

x                                  = 

x                                  = 1.750

Why (4 x 9,000)?

4 are from Tuesday and Friday in two Sunday. It means that there are 4 days.

{Why 2 (6x - 2x)?

2 is derived from 2 weeks while 6x - 2x derived from 6 days in one Sunday except Sunday because of a holiday, minus 2 days (Tuesday and Friday because it was rationed)} \
Thus, the allowance per day which we use in addition to Tuesday and Friday (once again because it has been rationed) and in addition to Sunday (for holidays) a maximum of Rp 1.750.