SOLUTION: Given that -5<= x <=3 and -8<= y <=6 where both x and y are integers, calculate; a) the greatest value of 2x+3y b) the least value of 3xy c) the greatest value of x^2+y^2 d) th

Algebra ->  Inequalities -> SOLUTION: Given that -5<= x <=3 and -8<= y <=6 where both x and y are integers, calculate; a) the greatest value of 2x+3y b) the least value of 3xy c) the greatest value of x^2+y^2 d) th      Log On


   

Question 1066719: Given that -5<= x <=3 and -8<= y <=6 where both x and y are integers, calculate;
a) the greatest value of 2x+3y
b) the least value of 3xy
c) the greatest value of x^2+y^2
d) the least value of x^2-y^2
Answer by Fombitz(32388) About Me  (Show Source):
You can put this solution on YOUR website!
Greatest value of a sum choose the greatest value for both variables,
2x%2B3y=2%283%29%2B3%286%29=6%2B18=24
24
.
.
.
Least value of a product choose the greatest of one variable and least value of the other variable, compare the products.
3xy=3%28-5%296=-90
3xy=3%283%29-8=-72
-90
.
.
.
Greatest value of sum of squares choose largest absolute value of both variables,
x%5E2%2By%5E2=%28-5%29%5E2%2B%28-8%29%5E2=25%2B64=89
89
.
.
Least value of x^2-y^2, choose largest value of absolute value of x and smallest value of absolute value of y,
x%5E2-y%5E2=%28-5%29%5E2-0%5E2=25
25