Step-by-step explanation:
15.50n +10=72
15.50×4+10=72
62+10=72
For any arbitrary 2x2 matrices

and

, only one choice of

exists to satisfy

, which is the identity matrix.
There is no other matrix that would work unless we place some more restrictions on

. One such restriction would be to ensure that

is not singular, or its determinant is non-zero. Then this matrix has an inverse, and taking

we'd get equality.
You subtract 16 from each side of the equation.
Then it will say exactly what number 'n' is.
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The equation is n + 16 = 9
On the left side, you subtract 16 from (n + 16) and you have 'n'.
On the right side, you subtract 16 from 9 and you have -7 .
Now the equation says n = -7