Question

Slove 8x+5y=9and 3x+2y=4 by stituting method

Answer 1

Answer :

x = -2 , y = 5

Solution :

Here ,

The given equations are ;

8x + 5y = 9 -------(1)

3x + 2y = 4 -------(2)

Considering eq-(2) , we have ;

=> 3x + 2y = 4

=> 2y = 4 - 3x

=> y = (4 - 3x)/2 ------(3)

Now ,

Putting y = (4 - 3x)/2 in eq-(1) , we have ;

=> 8x + 5y = 9

=> 8x + 5•(4 - 3x)/2 = 9

=> [ 2•8x + 5•(4 - 3x) ] / 2 = 9

=> 2•8x + 5•(4 - 3x) = 2•9

=> 16x + 20 - 15x = 18

=> 16x - 15x = 18 - 20

=> x = -2

Now ,

Putting x = -2 in eq-(3) , we have ;

=> y = (4 - 3x)/2

=> y = [4 - 3•(-2)]/2

=> y = (4 + 6)/2

=> y = 10/2

=> y = 5

Hence ,

x = -2 , y = 5 .

Answer 2

Answer:

substituting the value

Step-by-step explanation:

x=9-54/8.....(iii)

substituting the value of x in(ii) we get

3*9-54/8 + 2y=4

27-15y +16y =32

y 32-27 =5

substituting y in (iii) we get x=9-5*5/8 -16/8= -2

Hence,x= -2 and y = 5 is the solotion

this is the correct answer

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