Complete question :
Use this system of equations to answer the questions that what number would you multiply the second equation by in order to eliminate the x-terms when adding to the first equation?
What number would you multiply the second equation by in order to eliminate the y-terms when adding to the first equation?
4x – 9y = 7
–2x + 3y = 4
Answer:
2 ; 3
Explanation:
Given the equations :
4x – 9y = 7 - - - - - (1)
–2x + 3y = 4 - - - (2)
The number to multiply equation (2) by in other to eliminate the x-term :
We multiply equation (2) by 2 ; thus we have ;
4x - 9y = 7 - - - - (1)
-4x + 6y = 8 - - - - (2) ; adding (1) and (2)
___________
____ - 3y = 15
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The number to multiply equation (2) by in other to eliminate the y-term :
We multiply equation (2) by 3 ; thus we have ;
4x - 9y = 7 - - - - (1)
-6x + 9y = 12 - - - - (2) ; adding (1) and (2)
___________
-2x = 19
___________