Answer:
a+b=249/14
Step-by-step explanation:
z1= [-a+sqrt(a^2-4ab)]/2
z1= [-a-sqrt(a^2-4ab)]/2
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z1= -a/2+[sqrt(a^2-4ab)]/2
then,
-a/2=-7
so, a=14
a^2-4ab= -16
b=(a^2+16)/(4a)
b=53/24
therefore, a+b= 249/14