Let x be the number.
"twelve decreased by twice a number" ---> 12 - 2x
"8 times the sum of number and 4" ---> 8(x + 4)
12 - 2x = 8(x + 4)
12 - 2x = 8x + 32 (distributive property)
12 = 10x + 32 (add 2x to both sides)
-20 = 10x (subtract 32 from both sides)
x = -2 (divide both sides by 10)
Wouldn't all the angles equal 180? We've been trying to learn these but I think so. Subtract both numbers by 180 and it should be the answer. Sorry if it's wrong but I'm not sure. I kinda hope this helps you any
70,000 grams is 70 kilograms
5.5 × 2= 11
11 is the length.
perimeter= 11+11+5.5+5.5
The perimeter is 33 units.