Math home work help!!!!?

Question

1.) Mr. Co travelled 60km accross the countryside on a rainy day at a constant speed. If he had arrived in 30min. less time. How fast was he driving?

2.) A class decides to buy an algebra book for 160 pesos. Eight members in class were absent. The cost per student would have gona up to 1 peso..How many studets were in class??

uHmm.....please...help..

can you use variables x and y ...

or anything..

just show ur solutions..

big points for best answer:]

Answer 1

1- Speed = distance divided by time S= D divided by T

                 =60km divided by 30 min.

                 = 2 km per min



2-  a  x 1 = 160

     a= 160

Answer 2

The first question is not understandable to me. I will just walk past it as of now and proceed to the 2nd question.

Cost per class member (y):

y = 160/x

y + 1 = 160/(x - 8)

(y + 1)(x - 8) = 160

xy - 8y + x - 8 = 160

y(x - 8) = 160 - x + 8

y = (160 - x + 8)/(x - 8)

Find no. of class members (x):

160(x - 8) = x(160 - x + 8)

160x - 1,280 = 160x - x² + 8x

x² - 8x = 1.280

x² - 4x = 1,280 - 4²

x² - 4x = 1,280 + 16

(x - 4)² = 1,296

x - 4 = 36

x = 40

Answer: 40 are members of the class. They contribute P4 (P160/40) each but with the absence of 8 members the remaining members contribute P5 (P4 + P1) each.

Proof:

P4(40 members) = P5(40 - 8 members)

P160 =  P5(32 members)

P160 = P160

Answer 3

Could you please rephrase the actual problems? I'm having a hard time understanding.