1. **State the problem:** We are given a sequence starting with the first term unknown, and the term-to-term rule is "Multiply by a number then subtract 2". The sequence provided is 7, 12, 22, 42, ...
2. **Identify the term-to-term rule:** Let the multiplier be $m$. The rule is:
$$a_{n+1} = m \times a_n - 2$$
3. **Use the given terms to find $m$:**
From the first two terms:
$$12 = m \times 7 - 2$$
Add 2 to both sides:
$$12 + 2 = m \times 7$$
$$14 = 7m$$
Divide both sides by 7:
$$\frac{14}{\cancel{7}} = \cancel{7}m$$
$$2 = m$$
4. **Verify the rule with $m=2$ for the next terms:**
Check if $22 = 2 \times 12 - 2$:
$$2 \times 12 - 2 = 24 - 2 = 22$$ Correct.
Check if $42 = 2 \times 22 - 2$:
$$2 \times 22 - 2 = 44 - 2 = 42$$ Correct.
5. **Find the first term:** The first term is given as 7.
**Final answer:**
- First term: $7$
- Term-to-term rule: Multiply by $2$ then subtract $2$
Sequence Rule 76D97D
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