SOLUTION: solve the following by the elimination method 7x-4y=-30 and 3x+4y=10

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Question 583654: solve the following by the elimination method 7x-4y=-30 and 3x+4y=10
Answer by Maths68(1474) About Me  (Show Source):
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7x-4y=-30..........(1)
3x%2B4y=10..........(2)
Add (1) and (2)
7x-4y=-30
3x%2B4y=10
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10x=-20
cross%2810%29x%2Fcross%2810%29=cross%28-20%29%2Fcross%2810%29
x=-2
Put the value of x in (2)
3x%2B4y=10..........(2)
3%28-2%29%2B4y=10
-6%2B4y=10
4y=10%2B6
4y=16}
4y%2F4=16%2F4
cross%284%29y%2Fcross%284%29=cross%2816%29%2Fcross%284%29
y=4
x,y=-2,4

Check
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Put the value of x and y in (1)
7x-4y=-30..........(1)
7%28-2%29-4%284%29=-30
-14-16=-30
-30=-30
Put the value of x and y in (2)
3x%2B4y=10..........(2)
3%28-2%29%2B4%284%29=10
-6%2B16=10
10=10