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Using elimination method, simultaneously solve this equation: 2y+3x=7 and 4x+3y=15​

User Kleopatra
by
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1 Answer

2 votes

Answer: x = -9 , y = 14

Explanation:

3x + 2y = 7 ................ equation 1

4x + 3y = 15 .............. equation 2

Solving using elimination method , we have to decide the variable we are eliminating first , we could eliminate x or y. If we are to eliminate y first , we will multiply equation 1 by 3 and equation 2 by 2 so that the coefficient of y can be the same. The equation then becomes

3( 3x + 2y = 7 )

2 ( 4x + 3y = 15 )

Expanding , we have

9x + 6y = 21 ..................equation 3

8x + 6y = 30 ................ equation 4

Now that the coefficient of y is the same , we will subtract equation 4 from equation 3 to eliminate y , we have

x = -9

Substitute y = -9 into equation 1 to find the value of x , we have :

3( -9 ) + 2y = 7

-27 + 2y = 7

2y = 7 + 27

2y =34

y = 34/2

y = 14

User Alo
by
5.1k points
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