Banana Lemon Balance 322B4F
1. **State the problem:** We need to find the value of $A$ given three balancing scales involving bananas, pears, lemons, and peas.
2. **Assign variables:** Let
- $B$ = weight of one banana
- $P$ = weight of one pear
- $L$ = weight of one lemon
- $Pe$ = weight of one pea
3. **Translate the scales into equations:**
- Top-left scale: One pair of bananas balanced with one pair of pears means
$$2B = 2P \implies B = P$$
- Top-right scale: One pair of bananas and two lemons balanced with one pair of peas and seven bananas means
$$2B + 2L = 2Pe + 7B$$
Rearranged:
$$2L = 2Pe + 7B - 2B = 2Pe + 5B$$
- Bottom scale: One banana balanced with one lemon labeled as $x A$ means
$$B = L = xA$$
4. **Use $B = P$ and $B = L$ to substitute:**
From step 3, $L = B$, so substitute $L$ with $B$ in the second equation:
$$2B = 2Pe + 5B \implies 2Pe = 2B - 5B = -3B \implies Pe = -\frac{3}{2}B$$
5. **Interpretation:** The pea weight is negative relative to banana weight, which is unusual but mathematically consistent.
6. **Find $A$:** From the bottom scale, $B = L = xA$, so
$$A = \frac{B}{x}$$
Since $x$ is the label on the lemon in the bottom scale and the banana weight equals lemon weight, $A$ equals the banana weight divided by $x$.
**Final answer:**
$$A = \frac{B}{x}$$
Without numerical values for $B$ or $x$, this is the expression for $A$ based on the given scales.