Please help due at 8:00

x=6

Step-by-step explanation:

(whole secant) x (external part) = (tangent)^2

(12+x+9)*12 = 18^2

(21+x)12 =324

Divide each side by 12

(21+x) 12/12 = 324/12

21+x = 27

Subtract 21 from each side

21+x-21 =27-21

x=6

answer:

let x = final exam score

80 ≤ (77 + 81 + 80 + 88 + 3x)/7 ≤ 89

560 ≤ 326 + 3x ≤ 623

234 ≤ 3x ≤ 397

78 ≤ x ≤ 99

range: [78,99]

that's it! ; )

step-by-step explanation:

meh smart