Solve the system.
x-y =-1
x+z=-5
y-z=2​

x= -2

y= -1

z= -3

Step-by-step explanation:

x-y= -1 (1)

x+z= -5 (2)

y-z= 2 (3)

(1)+(3)==> x-z= 1 (4)

(4)+(2)==> 2x= -4 ==> x= -2

we replace x by its value in equation (2):

-2+z= -5 ==> z= -3

we replace z by its value in equation (3):

y-(-3)= 2 ==> y+3=2 ==> y= -1

use this formula:

p(a\b) = p(a and b)/p(b).

take it from here.