Yes "3x8 = 4x6" does illustrate the commutative property of multiplication.
<em>1) 5 c + 4 = - 26
5 c = -26 -4
5 c = -30
c = -30 / 5
c = -6 so correct option is B..
2) 3 x - x +2 = 12
2 x +2 = 12
2x = 12-2
2x = 10
x = 10/2
x= 5 so correct option is D
3 ) 3 ( x + 1 )+ 6 = 33
3x + 3 + 6 = 33
3x + 9 = 33
3x = 33-9
3x = 24
x = 24/3
x = 8 so correct option is B
4) y/-6=9
y=9 x -6
y= - 54 there is no such option i guess question is missing
5)(x + 4) /2 = 7
x +4 = 7 x 2
x + 4 = 14
x = 14-4
x = 10 so correct option is D
6)1/3 ( 2x - 8) = 4
2x/ 3 - 8 /3 = 4
2x - 8 / 3 = 4
2x - 8 = 4 x 3
2x - 8 = 12
2x = 12 + 8
2x = 20
x = 20/2
x = 10 so correct option is C
</em>
Answer:

Step-by-step explanation:
To factor the equation, break it into two binomials which multiply to make the equation. To write these binomials (x+a)(x+b), find factors which multiply to -20 and add to -1 for a and b.
20: 1, 2, 4, 5, 10, 20
-5+4 = -1

Answer:
161 cm
Step-by-step explanation:
Since 115 cm is 5 boxes, we take 115 and divide it by 5. This will get us the cm of 1 box. 115/5=23
Now we take 23 and multiply it by 7 to get the final height. 23x7=161