zenriek asked in Science & MathematicsMathematics · 1 decade ago

# Solve this system of equations. Use the inverse of the coefficient matrix.?

7x+3y+2z=13

-2x+y-8z=26

x-4y+10z=-13

What am I supposed to do?

How do I do this with a calculator (an online one)?

### 2 Answers

Relevance
• Anonymous
1 decade ago
Favorite Answer

You can do it in Excel!

inverse is

0.211538462 0.365384615 0.25

-0.115384615 -0.653846154 -0.5

-0.067307692 -0.298076923 -0.125

soln

9

-12

-7

• Anonymous
4 years ago

Subtract equation a million from equation 3 8x + 5y + 7z - 7x - 5y - 6 z = a million - a million = 0 x + z = 0 (A) Multiply equation 2 with 5 and upload equation a million 15x - 5y + 15z = 5 15x - 5y + 15z + 7x + 5y + 6z = 5 + a million =6 22x + 21z = 6 (B) From A x = -z Substituting cost of x in B 22( - z) + 21z = 6 -22z + 21z = 6 -z = 6 z = -6 x + z = 0 x -6 = 0 x = 6 changing values of x & z in equation 2 3 ( 6) - y + 3 ( -6) = a million -y = a million y = -a million answer x = 6 , y = -a million z= -6

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