Jack needs to earn a b in his algebra class. his current test scores are 77,81,80 and 88. his final exam is worth 3 test scores. in order to earn a b jack's average must lie between 80 and 89 inclusive. what range of scores can jack receive on the final exam to earn a b in the course?

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

step-by-step explanation: yes

341

step-by-step explanation:

all you have to do is 9x31 (which equals 279) and then 20x31 (which equals 620). then you have to subtract. 620-279=341.