Question

3x+4y=11;4x+3y=12...​

Answer 1

Answer:

3X + 4Y =11 ---------(1)

4X + 3Y =12 --------(2)

BY ASA (ADDITION, SUBTRACTION, ADDITION) METHOD.

ADDING EQUATION (1) AND (2)

3X+4Y=11

4X+3Y=12

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7X+7Y= 23 ---------(3)

SUBTRACTING EQUATION (1) BY (2)

4X+3Y=12

3X+4Y =11

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X - Y = 1 ----------(4)

MULTIPLYING EQUATION (4) BY 7

7X-7Y =7 -------(5)

ADDING EQUATION (3) AND (5)

7X + 7Y = 23

7X - 7Y = 7

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14X = 30

X = 30/14

X = 15/7

SUBSTITUTING X=15/7 IN EQUATION (4)

15/7 - Y = 1

-Y = 1 - 15/7

-Y = 7-15/7

-Y = -8/7

Y = 8/7

(X,Y) = (15/7,8/7)