Write an explicit formula for An, the nth term of the sequence 7, 42, 252, ...

Step-by-step explanation:

This is a geometric progression.

Givens

a1 = 7

r = 6

Formula

a_n = a1 * r^(n - 1)

a_n = 7 (6)^(n - 1)

Sample

Try n = 3

a_3 = 7*(6)^(3-1)

a_3 = 7*(6)^2

a_3 = 7 * 36

.a_3 = 252      which is exactly what it should be.

x= -3 and

step-by-step explanation:

to find the roots of a cubic, use division or factoring to find the factors then set equal to 0. as this is a difference of cubes, it factors into

where a is the cube root of .

here   this is 27 and the cube root of 27 is 3. so we write using the form:

.

set each factor to 0 and solve for x.

x-3=0

x=3

the quadratic expression does not factor and must be solved using the quadratic formula.

where a = 1, b=3, and c=9

this cubic has two complex roots.

the answer would be 484

step-by-step explanation:

just multiply 0.484 times 1,000 (formula)