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8x + y = 21 and 22x – 2y = 34

User Michael Mahony
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2 Answers

28 votes
28 votes
8x + y = 21
22x -2y = 34

(2, 5)
User Anders Gram Mygind
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23 votes
23 votes

8x + y = 21 (1)

22x - 2y = 34 (2)

To solve this system of the equation we will use the elimination method

Since y has opposite signs, then we will make their coefficients equal and add the equations

Multiply equation (1) by 2 to eleminate y

2(8x) + 2(y) = 2(21)

16x + 2y = 42 (3)

Now add equations (2) and (3)

(22x + 16x) + (2y - 2y) = (34 + 42)

38x + 0 = 76

38x = 76

Divide both sides by 38 to find x


(38x)/(38)=(76)/(38)

x = 2

Now let us find y

Substitute the value of x in equation (1) or (2) to find y

I will substitute it in (1)

8(2) + y = 21

16 + y = 21

Subtract 16 from both sides to find y

16 - 16 + y = 21 - 16

y = 5

The solution of the system of equation is (2, 5)

User Diogojme
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