1. We are given two problems involving simultaneous equations related to costs and numbers.
**Problem 1:**
The cost of 2 rackets and 3 squash balls is 21.63.
The cost of 5 rackets and 7 squash balls is 52.90.
Let $r$ represent the cost of one racket and $s$ the cost of one squash ball.
2. Set up the equations:
$$2r + 3s = 21.63$$
$$5r + 7s = 52.90$$
3. To solve, multiply the first equation by 5 and the second by 2 to eliminate $r$:
$$ (2r + 3s) \times 5 \implies 10r + 15s = 108.15 $$
$$ (5r + 7s) \times 2 \implies 10r + 14s = 105.80 $$
4. Subtract the second from the first:
$$ (10r + 15s) - (10r + 14s) = 108.15 - 105.80 $$
$$ s = 2.35 $$
5. Substitute $s = 2.35$ into the first equation:
$$ 2r + 3(2.35) = 21.63 $$
$$ 2r + 7.05 = 21.63 $$
$$ 2r = 21.63 - 7.05 = 14.58 $$
$$ r = \frac{14.58}{2} = 7.29 $$
**Answer for problem 1:**
- Cost of one racket $= 7.29$
- Cost of one squash ball $= 2.35$
**Problem 2:**
The cost of 7 potted plants and 2 bags of fertiliser is 43.
The cost of 5 potted plants and 4 bags of fertiliser is 41.
Let $p$ be the cost of one potted plant and $f$ be the cost of one bag of fertiliser.
Set up the equations:
$$7p + 2f = 43$$
$$5p + 4f = 41$$
Multiply the first by 2 and the second by 1 (to aid elimination of $f$):
$$14p + 4f = 86$$
$$5p + 4f = 41$$
Subtract the second from the first:
$$ (14p + 4f) - (5p + 4f) = 86 - 41 $$
$$ 9p = 45 $$
$$ p = 5 $$
Substitute $p = 5$ into the second equation:
$$ 5(5) + 4f = 41 $$
$$ 25 + 4f = 41 $$
$$ 4f = 16 $$
$$ f = 4 $$
Calculate the total cost of 2 potted plants and 5 bags of fertiliser:
$$ 2p + 5f = 2(5) + 5(4) = 10 + 20 = 30 $$
**Answer for problem 2:**
- Total cost of 2 potted plants and 5 bags of fertiliser $= 30$
Costs Simultaneous
Step-by-step solutions with LaTeX - clean, fast, and student-friendly.