Soal PTS Matematika Kelas 9 Semester 1 Tahun 2022 Part 3 Full Pembahasan Kunci Jawaban Lengkap

11. a

x = 3
3^2 + 4.3 + c = 0
9 + 12 + c = 0
c = -21

12. a

D = b^2 - 4ac
49 = (-5)^2 - 4.3.c
49 = 25 - 12c
12c = 25 - 49
12c = -24
c = -24/12
c = -2

Baca Juga: Kunci Jawaban PKN Kelas 9 Halaman 51, Uji Kompetensi Bab 2 Pembukaan UUD 1945

13. b

x = 3
x^2 + 2x - 15 = 0
3^2 + 2.3 - 15 = 0
9 + 6 - 15 = 0

x^2 + 2x - 15 = 0
(x + 5)(x - 3) = 0

x + 5 = 0
x = -5

x - 3 = 0
x = 3