Question

can someone help me on these two questions please for 86 points and i'll award someone the brainiest

Answer 1

5x +  2y = 13
 x  +  2y  = 9

Subtract  :-  ( note that 2y - 2y = 0):-

4x  + 0 = 4
x = 1 

From 2nd equation plug in x = 1

1 + 2y = 9
2y = 8
y = 4   

Solution to this equation is  x=1,y=4



2x + y = 7
5x - y = 14

Adding eliminates the y  terms because y + -y = 0 :-

7x + 0 = 21
7x = 21
x = 3

Plug x=3 into second equation:-

5(3) - y = 14 
y = 15-14 = 1

solution is x =3, y = 1

Answer 2

Answer:

1)   x = 1,   y = 5

2)   x = -7 , y = 21

Step-by-step explanation:

1) 5x + 2y = 13

     x + 2y = 9

5x + 2y - 13 = x + 2y - 9

combine like terms:

5x - x + 2y - 2y - 13 + 9 = 0

4x - 4 = 0

x = 4 / 4

x = 1   ----------plug in x=1 on equation x + 2y = 9

1 + 2y = 9

y = 10 / 2

y = 5

therefore x = 1, y = 5

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2)  2x + y = 7

    5x - y = 14

combine like terms:

2x + y -7 - 5x - y - 14 = 0

-3x - 21 = 0

x = 21/-3

x = -7  ----------plug in x=-7 on equation 2x + y = 7

2(-7) + y = 7

-14 + y = 7

y = 7 + 14

y = 21

therefore x = -7 , y = 21