9, 2, -5... so is going down by 7 each time, meaning the "common difference" is -7.

$\bf n^{th}\textit{ term of an arithmetic sequence}\\\\
a_n=a_1+(n-1)d\qquad 
\begin{cases}
n=n^{th}\ term\\
a_1=\textit{first term's value}\\
d=\textit{common difference}\\
----------\\
a_1=9\\
d=-7\\
a_n=-187
\end{cases}
\\\\\\
-187=9+(n-1)(-7)\implies -187=9-7n+7
\\\\\\
7n=9+7+187\implies 7n=203\implies n=\cfrac{203}{7}\implies \boxed{n=29}$

4 0

3 years ago

Solve the equation graphically: √ x = - x.

Nikolay [14]

Sqrt[x] = -x
x= x ^ 2
x - x^2 = 0
-x(x-1)=0
x(x-1)=0
x = 1 or x = 0
sqrt 1 isn not equal to 0

x= 0

6 0

4 years ago

a right triangle has a 30 degree angle. the leg adjacent to the 30 degree angle measures 25 inches. what is the length of the ot

crimeas [40]

The length of the other leg is 14.4

8 0

4 years ago