How do you solve ((8, 7), (1, 1))x=((3, -6), (-2, 9))?
1 Answer
Aug 14, 2018
Explanation:
Let's try multiplying both sides by
((1, -7),(-1, 8))((8, 7),(1,1))x=((1,0),(0,1))x = x
whereas:
((1, -7),(-1,8))((3,-6),(-2,9)) = ((17,-69),(-19,78))
So:
x = ((1, -7),(-1, 8))((8, 7),(1,1))x = ((1, -7),(-1,8))((3,-6),(-2,9)) = ((17,-69),(-19,78))
In general, the multiplicative inverse of
1/abs((a,b),(c,d)) ((d, -b),(-c, a))
and in our example:
abs((8, 7),(1, 1)) = 8 * 1 - 7 * 1 = 8 - 7 = 1