−2x(x+5) for x=−3
Idk what this mean plz help

12

Step-by-step explanation:

This means you should write out the equation and replace -3 with x

Given the equation −2x(x+5)

-2 (-3) (x +5)open the first bracket

6 ( -3 + 5) then open the second bracket

6 ( 2) = 6 x 2

= 12

I hope this is clear, please mark as brainliest answer.

Regular polygon area = n*side^2 / (4 * tan (180/n))
where "n" is number of sides
The formula is dependent on the side^2 term,
So, if we have an octagon that has sides 4 times as large, that means the area will be sixteen times larger.
side^2 = 4^2 = 16
So we multiply 25 cm^2 by 16 and we get
400 square centimeters.

Source:
http://www.1728.org/polygon.htm