9514 1404 393
Answer:
13 cm, 39 cm, 39 cm
Step-by-step explanation:
If x is the short side, then the other two sides are 3x and 3x. The perimeter is the sum of side lengths:
x +3x +3x = 91
x = 91/7 = 13
3x = 3(13) = 39
The length of the short side is 13 cm; the other two sides are 39 cm.
The correct answer is 140 because the mean, average, number from July per day represents how many people would have visited each day if they were all even.
If there were 20 more people each day in August, the mean would be 140. This would represent how many people visited each day.
Use substitution and substitute y into the other equation. One of the equations already gives you y in terms of x, so use that and substitute it into the other equation. y = 3x - 4
Plug into the other equation: -3y = -9x + 12
-3(3x-4) = -9x + 12
-9x + 12 = -9x + 12
This is an identity. So that means that any value of x makes this equation true. So B.
