K/3 + 4 -2k = -9k
First you add 9k to both sides
<span>k/3 + 4 -2k = -9k
</span> +9k +9k
<span>k/3 + 4 + 7k = 0
</span>
Now subtract 4 from both sides
k/3 + 4 + 7<span>k = 0
</span> -4 -4
k/3 + 7<span>k = -4
</span>
Now multiply 3 by both sides
k/3 + 7<span>k = -4
</span>x3 x3 x3
k +21k = -12
Now add k + 21k
22k = -12
Now divide both sides by 22
<span>22k = -12
</span>----- -----
22 22
k = -6/11
Mickey incorrectly calculated the unit price:

The correct operation is:

Each carton costs 1.85, so 7 cartons cost
Answer:
step 1. Angle bisector theorem.
step 2. 14/6 = 21/ (3x - 12)
step 3. 14(3x - 12) =21(6)
step 4. 6x - 24 = 18
step 5. 6x = 42
step 6. x = 7.