1) hasil pemfaktoran dari 12x^2 + 2xy - 10y^2 adalah..... 2) diketahui (x) = x^2 - 5n , jika f(5) = 10 maka nilai n adalah ...... tolong jawab pakai caranya ya

1)

12x^2 + 2xy - 10y^2
= 12x^2 + 12xy - 10xy - 10y^2
= 12x(x + y) - 10y(x + y)
= (12x - 10y)(x + y)
Bisa jg :
2(6x - 5y)(x + y)

2)

10 = 5^2 - 5n
10 = 25 - 5n
5n = 25 - 10
5n = 15
n = 15/5
n = 3

f(x) = x²-5n
f(5) => 5²-5n = 10
=> 25-5n-10 = 0
=> -5n + 15 = 0
=> -5n = -15
=> n = -15/-5
=> n = 3