Question

Given `[(2, 1),(-3, 4)], "X" = [(7),(6)]` the matrix X.

Answer 1

We have

`[(2, 1),(-3, 4)], "X" = [(7),(6)]`

Let X = `[(x),(y)]`

So, `[(2, 1),(-3, 4)][(x),(y)] = [(7),(6)]`

⇒ `[(2x + y),(-3x + 4y)] = [(7),(6)]`

2x + y = 7           ...(i)

–3x + 4y = 6       ...(ii)

Multiplying (i) by 3 and (ii) by 2, and adding

we get:

 6x + 33y = 21
–6x + 8y = 12   
         11y = 33
⇒ y = 3

From (i),

2x = 7 – 3

2x = 4

x = 2

So, X = `[(2),(3)]`