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11 votes
11 votes
Solve this System of Equations Algebraically

2x + 5y = -13
3x - 4y = -8

Answer Options :
( 4,1 )
( -4,1)
(4,-1)
(-4,-1)

User Fanor
by
2.7k points

1 Answer

15 votes
15 votes

Answer:

{x,y}={-4,-1}

Explanation:

Solve by Substitution :

// Solve equation [2] for the variable x

[2] 3x = 4y - 8

[2] x = 4y/3 - 8/3

// Plug this in for variable x in equation [1]

[1] 2•(4y/3-8/3) + 5y = -13

[1] 23y/3 = -23/3

[1] 23y = -23

// Solve equation [1] for the variable y

[1] 23y = - 23

[1] y = - 1

// By now we know this much :

x = 4y/3-8/3

y = -1

// Use the y value to solve for x

x = (4/3)(-1)-8/3 = -4

Solution :

{x,y} = {-4,-1}

User Lieve
by
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