Answer:
Step-by-step explanation:
a = 7 ; b = 1 ; c = -5
D = b² - 4ac
= 1 - 4*7*(-5)
= 1 + 140
= 141
x =( - b ± √D ) / 2a
= (-1 ± √141)/2*7
= (-1±√141) / 14
[tex]a = \frac{-1+\sqrt{141} }{14}= \frac{-1+11.87}{14}= \frac{10.87}{14}=0.78\\\\b = \frac{-1-\sqrt{141}}{14}= \frac{-1-11.87}{14}= \frac{-12.87}{14}=3.59\\\\\\[/tex]
(a -4 )(b -4) = (0.78 - 4)(-3.59-4) = (-3.22)(-7.59)
= 24.4398