<u>Case 1 :</u>
5 positive x-tiles = 5x
1 positive unit tile = 1
5 positive x-tiles and 1 positive unit tile = 5x + 1
<u>Case 2 :</u>
2 negative x-tiles = -2x
6 positive unit tiles = 6
so, 2 negative x-tiles and 6 positive unit tiles = -2x+6
We see that Gracia has represented the 1st case as 5x+(-1), which should be 5 positive x-tiles and 1 negative unit tile.
Hence the statement : 5 positive x-tiles and 1 positive unit tile to represent 5x+(-1) , explains Gracia's error.
B. Communitive property of addition
Hi!
These two angles are alternate interior angles, so they are congruent. Thus:
∠A = ∠B
6x + 5 = 4x + 45
Solve for x:
2x + 5 = 45
2x = 40
x = 20
Solve for ∠A by substituting in this value:
∠A = 6(20) + 5 = 125°
