A college student completed some courses worth 3 credits and some courses worth 4 credits. The student earned a total of 59 credits after completing 18 courses. how many courses worth 3 credits did the student complete? 5

13

20

39

Answer

13

Step by Step Solution

The answer is 13 because 13*3 = 39. 20 is impossible because that would total 60 credits. 5 isn't possible because then there would be no way to get 9 in the digits place.

point a is the center of the circle that passes through points e, f, and g and the center of the circle that passes through points x, y, and z.

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