A*b = 4
a+b = -5
a = -5-b
Substitute the value of a in first equation,Â
(-5-b)*b = 4
-b²-5b-4 = 0
-b²-b-4b-4 = 0
b(-b-1) 4(-b-1)= 0
b+4 = 0 Â OR Â -b-1 = 0
b = -4 Â OR b = -1
Substitute it in first equation,
a-4 = -5 Â Â OR Â a-1 = -5
a = -5+4 Â OR Â a = -5+1
a = -1 Â Â Â OR Â a = -4
So, a = -1 & b = -4 or vice versa
Hope it helped.