Question

Question 2. solve the system of equations using the inverse Matrix.a. ( -7, - 4)b. (7, 4)c. ( -123, 157)d. ( 123, - 157)

Answer 1

we have the system

7x-9y=13

-4x+5y=-8

in matrix notation

7 -9 x 13

=

-4 5 y -8

AX=B

where

A= 7 -9

-4 5

Find A^-1

Det A=(35-(36))

Det A=-1

the inverse matrix is equal to

-1 5 9 13 ------- > (5)(13)+(9)(-8) ------> -7

4 7 -8 (4)(13)+(7)(-8) -4

multiply by -1

-7*-1=7

-4*-1=4

therefore

the solution is (7,4)

option B