Answer:
second option is correct onee
Step-by-step explanation:
mark me brainliest
Given:
Consider the given equation is:

To find:
The missing exponent.
Solution:
Let x be the missing exponent. Then the given equation can be written as

It can be rewritten as:

![[\because a^ma^n=a^{m+n}]](https://tex.z-dn.net/?f=%5B%5Cbecause%20a%5Ema%5En%3Da%5E%7Bm%2Bn%7D%5D)
On comparing the coefficient of m, we get



Therefore, the value of the missing exponent is 8. So, the complete equation is
.
Let's factorise it :

![\: {\qquad \dashrightarrow \sf {x}^{3} (x + 3) + [-5(x + 3)] }](https://tex.z-dn.net/?f=%5C%3A%20%7B%5Cqquad%20%20%5Cdashrightarrow%20%5Csf%20%20%20%20%7Bx%7D%5E%7B3%7D%20%28x%20%2B%203%29%20%2B%20%5B-5%28x%20%2B%203%29%5D%20%20%7D)
Using Distributive property we get :



⠀
Therefore,

Answer:
length is 78
Step-by-step explanation:
Perimeter of rectangle is P = 2 (l +w)
278 = 2(l + 61)
l = 78