Identify Equations: Identify the system of equations:1. x1+x2+x3=−22. 3x1−4x3=223. x1+2x2+5x3=−18
Express x1: Use the first equation to express x1 in terms of x2 and x3:x1=−2−x2−x3Substitute this expression for x1 in the other equations.
Substitute in 2nd Eq: Substitute x1 in the second equation:3(−2−x2−x3)−4x3=22−6−3x2−3x3−4x3=22−6−3x2−7x3=223x2+7x3=−28
Substitute in 3rd Eq: Substitute x1 in the third equation:(−2−x2−x3)+2x2+5x3=−18−2+x2+4x3=−18x2+4x3=−16
Solve the System: Now solve the system:From 3x2+7x3=−28 and x2+4x3=−16, eliminate x2:Multiply the second equation by 3:3x2+12x3=−48Subtract this from the first modified equation:(3x2+7x3)−(3x2+12x3)=−28+48−5x3=20x3=−4
Find x2: Find x2 using x2+4x3=−16:x2+4(−4)=−16x2−16=−16x2=0
Find x1: Find x1 using x1=−2−x2−x3:x1=−2−0+4x1=2