Consider the graph of the line of best fit, y = 0.5x + 1, and the given data points.

which is the residual value when x = 2?

a.–2

b.–1

c.1

d.2

The residual value is the vertical distance between the observed value and the predicted value. In other words,

residual value = point in scatter plot - point in the line of best fit

When , the corresponding scatter plot point is at and the corresponding point in the line of best fit is [can be seen from the graph]

Hence,

residual value = . Answer choice B is correct.

ANSWER: B

hello from mrbilldoesmath!

answer:

(7 x + 6 y) (49 x^2 - 42 x y + 36 y^2)

discussion:

the trick is to recognize that 343 = 7^3 and 216 = 6^3 and, in general,

a^3 + b^3 =   (a + b) (a^2 - a b + b^2).

in our case

343x^3+216y^3   =   (7x)^3 + (6y)^3

so take a = 7x and b = 6y in the above equation to get the answer.

you,

mrb