Estimate the volume of the solid that lies below the surface z=xy and above the rectangle r. use a riemann sum with m=3, n=2, and take the sample point to be the upper right corner of each square.
r = {(x, y): 0< =x< =6, 0< =y< =4}

Asif spent $745.10 on 13 new file cabinets for his office. small file cabinets cost $43.50 and large file cabinets cost $65.95. write and solve a system of equations to find the number of small cabinets and large cabinets he purchased. determine if each statement is true or false. 1. he purchased 5 small cabinets. true or false 2. he purchased 7 large cabinets. true or false 3. he spent $527.60 on large cabinets. true or false