You have a rectangular prism box with length x+5 units, width x-5 units, and height x^2+25 units. For how many positive integer values of x is the volume of the box less than 700 units?
Multiply all of the dimensions to find the volume:
(x+5)(x-5) = x^2 - 25
(x^2-25)(x^2 +25)= x^4 - 625
this volume has to be less than 700 units^3
x^4 -625 < 700
x^4 < 1325
x< 6.033 so integers 1,2,3,4,5,6 would work for x BUT you cannot have a negative (or zero) dimension so ONLY the integer 6 will work....so only ONE integer value will work for volume <700 units^3