Answer:
Step-by-step explanation:
2x+3y=15
x-3y=18
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x=3y+18
2(3y+18)+3y=15
6y+36+3y=15
9y=15-36
9y=-21
y=-21/9
simplify
y=-7/3
x-3(-7/3)=18
x+7=18
x=18-7
x=11
Answer: x=11, y=-7/3. (11, -7/3).
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2x+3y=20
-2x+y=20
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4y=40
y=40/4
y=10
2x+3(10)=20
2x+30=20
2x=20-30
2x=-10
x=-10/2
x=-5
Answer: x=-5, y=10. (-5, 10).
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3x-4y=-5
-10x+4y=12
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-7x=7
x=7/-7
x=-1
3(-1)-4y=-5
-3-4y=-5
4y=-3-(-5)
4y=-3+5
4y=2
y=2/4
simplify
y=1/2
Answer: x=-1, y=1/2. (-1, 1/2).
