Exercise 1 Page 330

Let's call the amount of CD's Miguel can buy n. Since he pays $12 per CD, the total cost for the CDs is 12n. If we add the cost of a CD player, which is $38, we get an expression that describes the total cost for buying n CDs and a CD player. 12n+38Since Miguel has $ 100, the expression cannot exceed this amount. 12n+38≤ 100 Let's solve this inequality.

12n+38≤ 100

SubIneq

LHS-38≤RHS-38

12n≤ 62

DivIneq

.LHS /12.≤.RHS /12.

n≤ 62/12

UseCalc

Use a calculator

n≤ 5.16666 ...

Since Miguel cannot buy a fraction of a CD, we have to round this integer down to the nearest whole number, 5. We wouldn't be able to round it up, even if the quotient came out to be 5.999, as this would put his expenses above $100. This corresponds to option D.