A because I have done this before
Answer:
1.) 6
2.)6
3,)4
Step-by-step explanation:
I think these are the gcf of the numbers
Linear pair angles have too add to 180, so
5x+9+3x+11=180
8x+20=180
8x=160
x=20
so angle S is 5*20+9 = 109
angle T is 3*20+11 = 71
Formula for perimeter of a rectangle: P = 2W + 2L
Here, P = 2(x-3 ) cm + 2(3x+7) cm = 2x - 6 + 6x + 14 (cm)
Combine like terms: 8x + 8 cm (simplest form) This is the perimeter.
Now let x = 4: P(x=4) = 8(4) + 8 cm = 40 cm