Tolong di jawab dong, please

Mapel : Matematika
Kelas : VII SMP
Bab : Aljabar

Pembahasan :
1.

3x - 15x
= (3 - 15)x
= -12x

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2.

10y + (-2y)
= 10y - 2y
= (10 - 2)y
= 8y

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3.

5x + 3y - x + 4y
= (5 - 1)x + (3 + 4)y
= 4x + 7y

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4.

4x + 9y = 9y + 4x

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5.

2xy² - 4x²y + 9xy²
= (2 + 9)xy² - 4x²y
= 11xy² - 4x²y
= xy(11y - 4x)

karena variabelnya sama sehingga bisa dioperasikann
3x-15x =-12x
10y-2y=8y
5x-x+3y+4y = 4x+7y
nomor 4 gk bsa dioperasikan, karena variabelnya beda
xy(2y-4x+9y)= xy(11y-4x)