solve the stem of equation by substituion method.

(1/5)x + (2/3)y  =  -(3 1/5)

Problems are usually easier if there are no fractions:

(1/5)x + (2/3)y  =  -16/5

Multiplying both sides by 15:

--->   3x + 10y  =  -48

Substitution can occur when one of the equations is solved for one of the variables.

Since the other equation is  3x - y  =  6 

this equation can be solved for y:  --->  -y  =  -3x + 6     --->     y  =  3x - 6

Substitute this value for  y  into the other equation:

--->   3x + 10y  =  -48    --->     3x + 10(3x - 6)  =  -48

                                    --->     3x + 30x - 60  =  -48

                                    --->     33x - 60  =  -48

                                    --->     33x  =  12

                                    --->     x  =  12/33     --->     x  =  4/11

If  x  =  4/11,  then  y  =  3x - 6     --->     3(4/11) - 6  =  -54/11