1. Solve Equations 2x+5y=21,x+2y=8 using Inverse Matrix method
Solution:
Here `2x+5y=21`
`x+2y=8`
Now converting given equations into matrix form
`[[2,5],[1,2]] [[x],[y]]=[[21],[8]]`
Now, A = `[[2,5],[1,2]]`, X = `[[x],[y]]` and B = `[[21],[8]]`
`:. AX = B`
`:. X = A^-1 B`
`=2 × 2 - 5 × 1`
`=4 -5`
`=-1`
`"Here, " |A| = -1 != 0`
`:. A^(-1) " is possible."`
`"Now, "A^(-1)=1/|A| × Adj(A)`
`"Here, "X = A^(-1) × B`
`:. X = 1/|A| × Adj(A) × B`
`:.[[x],[y]]=[[-2],[5]]`
`:. x=-2, y=5`
This material is intended as a summary. Use your textbook for detail explanation.
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