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Find the intersection of the lines 9x-4y=30 and 7x+y=11. Express your answer as an ordered pair (x,y).

 Nov 19, 2020
 #1
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9x - 4y  = 30       (1)

7x + y =  11    →   y = 11 - 7x       (2)

 

Sub (2) into (1)

 

9x - 4(11 - 7x)  = 30

 

9x - 44 + 28x    = 30

 

37x =  30 + 44

 

37x  = 74

 

x = 74/37  =  2

 

y = 11 - 7(2) 

 

y = 11 - 14

 

y = -3

 

Intersection  =  (2, -3)

 

cool cool cool

 Nov 19, 2020

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