Question

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)

Answer 1

Just multiply the matrices
a = (1)(-5)+(-2)(7)
b = (1)(6)+(-2)(-8)
c = (3)(-5)+(3)(7)
d = (3)(6)+(3)(-8)

Answer 2

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?