Image Attached, Complete the square. Fill in the number that makes the polynomial a perfect-square quadratic. Will give Brainliest

169

Step-by-step explanation:

You should know that the middle number with the x is double the original number not in expanded form. You should also know that in the expanded form, the last number is the square of the original number. So square(26/2) = 169.

r^2 + 26r = (r + 13)^2 - 169

Step-by-step explanation:

r^2 + 26r + (26/2)^2 - (26/2)^2, or

r^2 + 26r + 13^2 - 13^2, or

(r^2 + 26r + 169) - 169

So r^2 + 26r = (r + 13)^2 - 169

Note:  the coefficient of r is 26.  We take half of that, obtaining 13, and then square the result:  13.

the equation cos(35) =a/25 can be used to find the length of bc what is the length of bc? round to the nearest tenth

step-by-step explanation: