Answer:
Step-by-step explanation:
hello :
1)Two numbers have a product of 12 but their sum is -7 :
means : xy=12 ....(*)
x+y = -7 ....(**)
solve this system : use (**) you have x = -y-7 put this value in (*)
so : (-y-7)y = 12
-y²-7y-12 = 0
y² +7y+12=0 a=1 b=7 and c= 12
the discriminant delta =b²-4ac delta = 7²-4(1)(12) = 1
y1 = (-7-1)/2 = -4 and y2 = (-7+1)/2 =-3
but x= -7-y
if :y = - 4 x= -7-(-4) =-3
if : y=-3 x = -7-(-3) =-4
2) same method : xy=-30
x+y=1
