Question 881753
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n+d+q=25
.05n+.10d+.25q=3.80
0n+1d-1q=1

1,1,1,25
5,10,25,380
0,1,-1,1

Your matrix

№	n	d	q	b
1	1	1	1	25
2	5	10	25	380
3	0	1	-1	1
Write the main matrix

№	n	d	q
1	1	1	1
2	5	10	25
3	0	1	-1
Determinant is not zero, therefore inverse matrix exists


Calculate the inverse matrix

 n	d	q
 1.4	-0.08	-0.6
-0.2	0.04	0.8
-0.2	0.04	-0.2

Multiply the inverse matrix by the solution vector

№	X
n	4
d	11
q	10



n = 4
d = 11
q= 10