Question

4x+3y=24 and 3x+4y=25 solve by Cross multiplication.
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Answer 1

Step-by-step explanation:

We Have :-

$4x + 3y = 24 \\ \\ \\ 3x + 4y = 25$

To Find :-

$x \: and \: y$

Formula Used :-

$cross \: multiplication$

Solution :-

$4x + 3y = 24 \\ \\ \\ 3x + 4y = 25 \\ \\ \\ \dfrac{x}{b_{1}c_{2} -b_{2}c_{1}} = \dfrac{y}{c_{1}a_{2} -c_{2}a_{1}} = \dfrac{1}{a_{1}b_{2} -a_{2}b_{1}} \\ \\ \\ \dfrac{x}{3 \times 25 -4 \times 24} = \dfrac{y}{24 \times 3 -25 \times 4} = \dfrac{1}{4 \times 4-3 \times 3} \\ \\ \\ \dfrac{x}{3 \times 25 -4 \times 24} = \dfrac{y}{24 \times 3 -25 \times 4} = \dfrac{1}{4 \times 4-3 \times 3} \\ \\ \\ \dfrac{x}{ - 21} = \dfrac{y}{ - 28} = \dfrac{1}{4} \\ \\ \\ x = \dfrac{ - 21}{4} \\ \\ \\ y = - 7$

Answer 2

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QUESTION :

4x+3y=24 and 3x+4y=25 solve by Cross multiplication.

SOLUTION :

=> X / { 3 × 25 - 4 × 24 } = Y / { 24 × 3 - 25 × 4 }

= 1 / { 4 × 4 - 3 × 3 }

=> X / { 75 - 96 } = Y { 72 - 100 } = 1 / { 16 - 9 }

=> X / { -21 } = Y / { - 28 } = 1 / 7

=> X / { -21 } = 1 / 7

=> X = { -21 / 7 }

=> X = -3

We need to solve similarly for Y

Y/ { -28 } = 1 / 7

=> Y = { -28 / 7 }

=> Y = -4

Hence we find that X = -3 and Y = -4 are the roots of the equations given above .

Answer :

Solving the equations 4x+3y=24 and 3x+4y=25 by the method of Cross multiplication, we get the following answer :

X = -3

Y = -4

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