How many solutions does the system of equations below have?3x+y+2z=−15−3x−y−2z=15−2x−2y+z=12Choices:(A)no solution(B)one solution(C)infinitely many solutions
Q. How many solutions does the system of equations below have?3x+y+2z=−15−3x−y−2z=15−2x−2y+z=12Choices:(A)no solution(B)one solution(C)infinitely many solutions
Addition of Equations: Add the first two equations to see if they cancel each other out.3x+y+2z=−15−3x−y−2z=15-----------------0=0
Verification of Equations: Since 0=0 is a true statement, it means the first two equations are multiples of each other and represent the same plane.
Checking Third Equation: Now, check if the third equation is also a multiple of the first one.−2x−2y+z=12If we multiply the first equation by −2/3, we should get the third equation if they are the same plane.(−2/3)(3x+y+2z)=(−2/3)(−15)−2x−(2/3)y−(4/3)z=10This is not the same as the third equation, so there is a mistake here.
More problems from Determine the number of solutions to a system of equations in three variables