Question

Evaluate the expression. 2x - 3y for x = 3, y = -4
a) 18
b) -2
c) 20
d) 13

Answer 1

12+6=18 So the answer is 18 because if we feel the value of x and y. And then 2(3)-3(-4)=6+12=18. OK bro

Answer 2

just substitute it, 

2X  - 3Y =  ((2)(3) )  -    ((3)*(-4))
            
                  (6)   -    (-12)
             NEGATIVE* NEGATIVE GIVES POSITIVE
                     6 +12  = 18