Help me so solve this

Below.

Step-by-step explanation:

Finding the derivative:

y' = 10x + 12.

At x = -5 ,  y' = -50+12 = -38.

This means the function is decreasing at this point.

The second derivative is 10 (positive) so it is convex at this point.

to find the perimeter of the rectangle this is the expression:

x-9+x-9+3x-4+3x-4=138

if we simplify it:

8x-26=138

remember, 138 is what it all adds up to

the length is 11.5cm

the width is 57.5cm

the area is 661.25cm^2

the answers might not be correct use at own risk

are ya tryin to ask something or is this a statement