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

the correct answer is option c.   3

step-by-step explanation:

points to remember

equation of the line with coordinates (x₁, y₁) and (x₂, y₂) is given by,

slope m = (y₂ - y₁)/(x₂ - x₁)

from the figure we can see a line with two coordinates given

to find the slope of given line

here   (x₁, y₁)   = (-1, -1 ) and (x₂, y₂) = (1, 5)

slope m = (y₂ - y₁)/(x₂ - x₁)

  = (5 - -1)/(1 - -1)

  = (5 + 1)/(1 + 1)

  = 6/2 = 3

therefore the correct answer is option c.   3

center (1,3) with radius 6

step-by-step explanation:

we must complete the square to find the center and radius of the circle.

first make sure the x and y squared terms have 1 as their coefficients. we also make sure x and y terms together.

we now create space between the x and y terms with parenthesis.

we complete the square by taking the middle terms -2x and the -6y - divide each and square them.

we add the squares to both sides.

simplify.

and write the quadratics in factored form.

the center is (h,k) or (1,3). the radius is the square root of 36 which is 6.