Question

Question 2
The coach of a cricket team buys 3 bats and 6 balls for Rs 3900. Later, she buys another bat and 2 more balls of the same kind for Rs 1300. Represent this situation algebraically and geometrically.

Answer 1

Let cost of one bat = Rs x
Cost of one ball = Rs y
3 bats and 6 balls for Rs 3900.
So,
3x + 6y = 3900 … (i)
Dividing equation by 3, we get;
x + 2y = 1300
Subtracting 2y both side we get;
x = 1300 - 2y
Putting y = -1300, 0 and 1300 we get
x = 1300 - 2 (-1300) = 1300 + 2600 = 3900
x = 1300 -2(0) = 1300 - 0 = 1300
x = 1300 - 2(1300) = 1300 - 2600 = - 1300
$\begin{array}{cccc}x& 3900& 1300& -1300\\ y& -1300& 0& 1300\end{array}$
Given that she buys another bat and 2 more balls of the same kind for Rs 1300.
So, we get,
x + 2y = 1300 … (ii)
Subtracting 2y both side we get,
x = 1300 - 2y
Putting y = - 1300, 0 and 1300 we get,
x = 1300 - 2 (-1300) = 1300 + 2600 = 3900
x = 1300 - 2 (0) = 1300 - 0 = 1300
x = 1300 - 2(1300) = 1300 - 2600 = -1300
$\begin{array}{cccc}x& 3900& 1300& -1300\\ y& -1300& 0& 1300\end{array}$
Algebraic representation:
3x + 6y = 3900 … (i)
x + 2y = 1300 … (ii)
Graphical representation: