Find the sum of the first six terms in the sequence (1,5,9,13)

The sum is 66  

Step-by-step explanation:

There are a couple formulas to remember.

aₙ = a₁ + d(n-1)

Sₙ = · (a₁ + aₙ)

In your case "d" equals 4 and a₁ equals 1, that's how we know what the sequence will progress.

Let's plug in the values for the first equation:

aₙ = 1 + 4 (n-1)

Next we can simplify:

aₙ = 1 + 4n-4

aₙ = 4n - 3

Now we can plug in the value for "n" which is 6 for this particular problem:

a₆ = 4 · 6 - 3

a₆ = 21

We can now use the second equation to find the sum:

S₆ = · (1 + 21)

S₆ = 66    

Hope this helps =)

step-by-step explanation:

there is a formula i can give you:

it is r^2*n*sin(360/n) divided by 2 where r represents the "radius" and n is the number of sides.

plug them in:

(10sqrt(3))^2*6*sin(360/6) divided by 2

100*3*6*sin(60) divided by 2

900*sin(60)

900*sqrt(3)/2

450*sqrt(3)

approx is 779.4 cm^2

the formula of a slope:

we have the points (-2, 7) and (2, 3). substitute: