answer:
k = 10
Explanation:
objective: get k by itself on one side of the equal sign
1. distribute the 10 to (k - 9) by multiplying these values by the outside value
10 × k = 10k
10 × -9 = -90
new equation: 10 = 10k - 90
2. get rid of 90 by doing the opposite (so we add 90) and what we do on one side we do to the other
(10k - 90) + 90 = 10k (90 cancels out)
10 + 90 = 100
new equation: 100 = 10k
3. get k by itself by dividing by 10 - since 10 is being multiplied by we need to get rid of it by doing its opposite (division) and doing this on both sides
10k ÷ 10 = k (the 10 cancels out)
100 ÷ 10 = 10
new equation: 10 = k
is k by itself? yes so k is equal to 10