Answer:
P = 12 + 5x
Step-by-step explanation:
P = a + b + c
P = 7 + (x + 4) + (4x + 1)
= 7 + x + 4 + 4x + 1
= 12 + 5x
Answer: 
Step-by-step explanation:


Answer:
x = -4 y = -5
Step-by-step explanation:
2x + 3 = -x - 9
3x + 3 = -9
3x = -12
x = -4
y = - (-4) - 9
y = 4 - 9
y = -5