I need help with #7. Please help. I have to show all work so please explain
1 answer:
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Answer:
Option A is correct (17,11).
Step-by-step explanation:
6x - 9y = 3
3x - 4y =7
it can be represented in matrix form as
A=
X=
B=
i.e, AX=B
or X= A⁻¹ B
A⁻¹ = 1/|A| * Adj A
determinant of A = |A|= (6*-4) - (-9*3)
= (-24)-(-27)
= (-24) + 27 = 3
so, |A| = 3
Adj A=
A⁻¹ = /3
A⁻¹ =
X= A⁻¹ B
X=
X=
X=
X=
x= 17, y= 11
solution set= (17,11).