Answer:
19. 16x-4 ; 20. 10y+1
Step-by-Step explanation:
19. The perimeter of a rectangle is expressed as P= 2(side1) + 2(side2)
If side1= x-3 and side2= 7x+1
P=2(x-3) + 2(7x+1)
=(2x-6) + (14x+2)
P=16x-4
or
P=4(4x-1)
20. The perimeter of a triangle is expressed by adding all three sides together.
If side1=3y+5 side2=y-4 side3=6y
P=(3y+5)+(y-4)+(6y)
P=10y+1
