The sum of a negative number and six is less than or equal to five.

-x≤-1

Step-by-step explanation:

Let x be the unknown number. We know x is negative, so we put a negative sign in front of it. Sum is the answer of adittion, so we add 6. We also know that 5 is more than or equal to -x+6.

-x+6 ≤ 5

We can simplify the answer by subtracting six on both sides and then dividing by -1 on both sides.

-x≤-1

x≤1

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