Lúcia is using energy at a rate of 420 kilocalories (kcal) per hour (h) ice skating. at what rate is lúcia using energy in calories per minute (cal/min)?

7,000 calories or 7 kilo cal/min.

Step-by-step explanation:

Lucia is using energy at a rate of 420 kilo calories per hour ice skating.

1 kilo calories = 1000 calories

420 kilo calories = 420,000 calories

1 hour = 60 minutes

∵  Lucia is using energy per 60 minutes =  420,000 calories

∴ She is using energy per minute =

                                                       = 7,000 calories or 7 kilo calories

Lucia is using energy 7,000 calories/minute.

answer: i believe the answer is e

step-by-step explanation:

hello from mrbilldoesmath!

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

discussion:

in general, the factorization of a^3 + b^3 is

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

in our case note that 343 = 7^3 and 216 = 6^3 so the equation becomes:

343x^3 + 216y^3 = (7x)^3 + (6y)^3

if you think of a (above) as 7x and b as 6y the factorization becomes

343x^3 + 216y^3 =

((7x + 6y) (   (7x)^2 - 7x*6y + (6y)^2)   =

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

you,

mrb

(a + b) (a^2 - a b + b^2)