Which number in the monomial 215x^18y^3z^21 needs to be changed to make it a perfect cube ?

Hello from MrBillDoesMath!

 215

Discussion:

Let's start by rewriting the monomial as

215  x^18 y ^3 z^21

Now..

x^ 18 = (x^6)^3

y^3   = (y    )^3

z^21 =  (z^7)^3

So those terms are already cubes!  The only remaining candidate is the number 215, which is not a cube.

Thank you,

MrB

b. an equilateral triangle inscribed in a circle

step-by-step explanation:

we are given the figure of two circles having a triangle inside.

now, we know that,

"when a figure is lying inside an another figure, then the outside figure is known as circumscribed figure and the figure lying inside is referred to as the inscribed figure".

as we see that, the circles are containing the triangle completely.

thus, the circles are the circumscribed figures and the triangle is the inscribed figure.

hence, we get, 'an equilateral triangle is inscribed in a circle'.

answer: -8.2562234e+13