The roots of 7x^2 + x - 5 = 0 are a and b. Compute (a - 4)(b - 4). Thank you!

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

(a -4 )(b -4) = (0.78 - 4)(-3.59-4) = (-3.22)(-7.59)

= 24.4398

the mean and mad

step-by-step explanation:

$4034.40

the perimeter of the field is the sum of the lengths of the four sides:

47 yd + 158 yd + 47 yd + 158 yd = 410 yd

the cost of 3 ft (1 yd) of fence is 3×$3.28 = $9.84.

so the cost of jake's wood perimeter fance is

(410 yd) × ($9.84 /yd) = $4034.40