Question 256255
with two equations and two unknowns, there are various methods of solution


in this case, the easiest is to add the equations


y= x-1
y= -x +7
_________
2y = 6


so, y=3 ____ substituting ___ 3 = x-1 ___ so, x=4





another technique is to substitute at the start ___ in this case, for the y value


x - 1 = -x + 7 ___ 2x = 8 ___ again, x = 4


then substitute to find y ___ y = 4 - 1 ___ y = 3




the choice of the method of solution is usually a combination of the complexity of the problem and personal preference