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)
Answer:
11.2
Step-by-step explanation:
a right triangle in an octagon is 1/2 a side length so to find the side length you must add .7 + .7. Next to find the perimeter of the octagon you must multiply the number of sides 8 by .14 which equals 11.2
4x = 157.2
4x/4 = 157.2/4
x = 39.3
(3x+2)-(2x-2)
3x+2-2x-2
3x-2x=x
2-2+0
X