Answer: 
<u>Step-by-step explanation:</u>
P = 2(l + b)
Divide both sides by 2:

Subtract b from both sides:

<em>Note: You can also multiply b by </em>
<em> if you want the left side to be one fraction.</em>

Make sure your calculator is in degree mode
Answer:
x=1 and y= -4
Step-by-step explanation:
step one: plug -4x into y in thi]e first equation.
2x+5(-4)= -18
step two: solve for x
2x-20= -18
(add 20 to both sides to eliminate -20 on the right)
2x=2
(divide both sides by 2 to get x by its self)
x=1
step 3: now that we found the value for x plug it in to either equation and solve for y
y= -4x
y= -4(1)
y= -4