Simplify the following rational expressions.
a. (1 / y − 1 / x) / (x / y − y / x)
b. (1 / x + 1 / y) / 1 / x^2 − 1 / y^2)
c. (1 / x4 − 1 / y2 )/ (1 / x4 + 2 / x2y+ 1 / y2)
d. (1 / x − 1 − 1 / x) / (1 / x − 1 + 1 / x)

Which ahows the graph of the solution set of 6x+4y< 12

Find the area of the unshaded square

Acompany manufactures three types of cabinets. it makes 110 cabinets each week. in the first week, the sum of the number of type-1 cabinets and twice the number of type-2 cabinets produced was 10 more than the number of type-3 cabinets produced. the next week, the number of type-1 cabinets produced was three times more than in the first week, no type-2 cabinets were produced, and the number of type-3 cabinets produced was the same as in the previous week.