Discrete Mathematics
posted by Joy on .
16. What is the value of a that would make the matrix equation true?:
( 1 2) (5 6) (a b)
( 3 4) (7 8) = (c d)

Just multiply the matrices
a = (1)(5)+(2)(7)
b = (1)(6)+(2)(8)
c = (3)(5)+(3)(7)
d = (3)(6)+(3)(8) 
For the matrices I came up with the following:
a. 5 + 14 = 19
b. 6 + 16 = 22
c. 15 + 21 = 6
d 18 + 24 = 6
Is this right? What am I suppose to do afterwards?