Solve for matrices 3x-y=2 x+2y=10

Question

step by step please? 

Answer 1

Solve using algebra:

solve eqt. #1 for "Y" 

y=3x-2

 

substitute into eqt #2

x+2(3x-2)=10

solve this eqt. for "X" then return to the above eqt. and solve for "Y"

 

Solving using matrix: note semi-colon means start of a new row

rewrite the system of eqt. as 2x3 matrix 

(3,-1,2;1,2,10) next rewrite this 2x3 matrix as a 3X3 

 

(3,-1,2,;1,2,10;0,0,0) use row reduction to obtain

(1,0,2;0,1,4;0,0,0)

solve for "x"  setting row 1 equal to 2 and "y" setting row 2 equal to 4