hi!(Hi)

i have trouble with the simplex method, i know how to solve if there is for example <= in the system but i don't know if there is only = because i don't know wich variable to take as basic variable (ex. x_11= 5- x_12)

x_11 + x_12=5

x_21 + x_22=7

x_11 + x_21=4

x_12 + x_22=8

x_ij>= 0 ,i=(1,2) ; j=(1,2)

min z=x_11+2x_12+2x_21+3x_22

i would be really thankful if someone can help me beacuse i have tomorrow a test (Worried)