Tolong jawab ya, harus segera dikumpulkan​

Penjelasan dengan langkah-langkah:

1.a

y = 2x² – 5x

persamaan sumbu simetri

x = -b/2a

x = -(-5)/2(2)

x = 5/4

1.b

y = 3x² + 12x

persamaan sumbu simetri

x = -b/2a

x = -12/2(3) = -12/6

x = -2

1.c

y = 8x² – 16x – 1

persamaan sumbu simetri

x = -b/2a

x = -(-16/2(8) = 16/16

x = 1

2.a

y = 6x² + 24x – 19

persamaan sumbu simetri

x = -b/2a

x = -24/2(6) = -24/12

x = -2

subtitusikan nilai x = -2 kepersamaan

y = 6(-2)² + 24(-2) – 19

y = 24 – 48 – 19

y = -43

nilai optimumnya = -43

2.b

y = 2/5x² – 3x + 15

persamaan sumbu simetri

x = -b/2a

x = -(-3)/2(2/5) = 3/(4/5) = 3 * 5/4

x = 15/4

subtitusikan nilai x= 15/4 kepersamaan

y = 2/5(15/4)² – 3(15/4) + 15

y = 2/5(225/16) – 45/4 + 15

y = 45/8 – 45/4 + 15

y = 45/8 – 90/8 + 120/8

y = 75/8

nilai optimumnya = 75/8