15x = 5y divide by 3, 3x=y. I believe
20 Answer: a₁ = 4
<u>Step-by-step explanation:</u>

21 Answer: n = 13
<u>Step-by-step explanation:</u>

22 Answer: n = 5
<u>Step-by-step explanation:</u>

the formula for a horizontal shift is (x-a) and this graph has moved 2 units to the left, -2, so the formula becomes (x+2)
The dependent value is determine by the value of the independent value. in other words, the dependent value is what you get when you take the independent value and substitute it in the original equation or situation. The relationship is multiplicative because you must first multiply the independent value in the equation where the x is before you can add or subtract to get your answer.<span />