Solve this: Find the product of the matrices A=-51371-51-11 and B= 112321213 and solve the equation using matrix method x+y+2z - Maths - Matrices

Question

Solve this:
Find the product of the matrices A = - 5 1 3 7 1 - 5 1 - 1 1  
a n d   B =   1 1 2 3 2 1 2 1 3 and solve the equation
using matrix method x+y+2z = 1, 3x+2y+z = 7 and 2x+y+3z =
2

Varun Rawat · Accepted Answer

The given equations are :x + y + 2z = 1 3x + 2y + z = 72x + y + 3z = 2Let B = 112321213; X = xyz; C = 172So, given system of equations is BX = CNow, AB = -51371-51-11112321213=-5+3+6-5+2+3-10+1+97+3-107+2-514+1-151-3+21-2+12-1+3=400040004=4IAB = 4I⇒14A 
 B = I⇒B-1 = 14A = 14-51371-51-11Now, BX = C⇒X = B-1C =14-51371-51-11 172⇒ xyz=14-5+7+67+7-101-7+2 = 21-1⇒x = 2; y = 1; z = -1

Solve this: Find the product of the matrices A = - 5 1 3 7 1 - 5 1 - 1 1 a n d B = 1 1 2 3 2 1 2 1 3 and solve the equation using matrix method x+y+2z = 1, 3x+2y+z = 7 and 2x+y+3z = 2.

Solve this:
Find the product of the matrices $A = |\begin{matrix} - 5 & 1 & 3 \\ 7 & 1 & - 5 \\ 1 & - 1 & 1 \end{matrix}| a n d B = |\begin{matrix} 1 & 1 & 2 \\ 3 & 2 & 1 \\ 2 & 1 & 3 \end{matrix}|$ and solve the equation using matrix method x+y+2z = 1, 3x+2y+z = 7 and 2x+y+3z = 2.