Sydney ran 400 meters in 1 minute and 20 seconds. What was Sydney's average rate in meters per second?

5 m/sec

Step-by-step explanation:

Let's first convert 1 min 20 sec into only seconds: 1 min = 60 sec --> 60 + 20 = 80 sec

So, Sydney ran 400 meters in 80 seconds. To find out her rate in meters per second, we need to divide 400 by 80: 400/80 = 5

Thus, her average rate was 5 meters per sec.

Hope this helps!

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)

it has to have an angle of 90 degrees