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Solve the linear systems using addition or subtraction 7x + 2y = 8;-5x - 2 =-12​

Respuesta :

anime1272006

Answer:

(2 , -3)

Step-by-step explanation:

7x +2y = 8

-5x - 2  = -12

The only method that uses addition/subtraction is elimination

5(7x + 2y = 8)

7(-5x = 10) I am getting x coefficient to be the same, LCF of 7 and 5 is 35)

(multiply it out and now we can get ready to subtract) *I got 10 by adding 2 to -12*

35x + 10y = 40

-35x = 70

10y = -30

y = -3

substitute y into original equation

7x + 2 (-3) = 8

7x - 6 = 8

7x = 14

x = 2

(2 , -3 )

charlief22

Answer:

Step-by-step explanation:

Add 5x to both sides to isolate -2:

-5x + 5x - 2 = -12 + 5x

-2 = -12 + 5x

Add 12 to both sides to isolate the 5x:

-2 + 12 = -12 + 12 + 5x

10 = 5x

Divide both sides by 5:

[tex]\frac{5x}{5} = 10 \div 5\\[/tex]

x = 2

Substitute this value into the first equation:

7x + 2y = 8

7(2) + 2y = 8

14 + 2y = 8

Subtract 14 from both sides:

14 - 14 + 2y = 8 - 14

2y = -6

Divide both sides by 2:

2y ÷ 2 = -6 ÷ 2

y = -3

So the coordinate set is:

(2, -3)

Hope this helps!

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