Question

Solve this system. Write your answer as an ordered pair.

y = -3 + 5x

3x - 8y = 24

(0, -3)
(0, 3)
(3, 0)
(-3, 0)

Answer 1

y = -3 + 5x ----------------- (1)
3x - 8y = 24 --------------- (2)     

Solve by substitution. We will substitute equation (1) into equation (2):

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Substitute equation (1) into equation (2) :
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3x - 8y = 24                 // Equation (2)
3x - 8(-3 + 5x) = 24      // Sub x = -3 + 5x
3x + 24 - 40x = 24        // Apply distributive property
-37x + 24 = 24              // Combine like terms      
-37x = 0                        // Take away 24 from both sides
x = 0                             // Divide by -37 on both sides

Sub x = 0 into equation (1) :
y = - 3 + 5(0)                   // Sub x = 0
y = -3                               // Combine like terms

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Answer : The ordered pair is (0, -3).
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