tolong bantu jawab pakai cara ya:)

y = 2x+a
2x = y-a
x = y-a / 2
f'x = x-a / 2

f(2x+a) = 3x+4a
fx = 3f'x + 4a
= 3(x-a / 2) + 4a
= 3x-3a / 2 + 4a
= 3x-3a+8a / 2
fa = 3a-3a+8a / 2
= 8a/ 2
2 = 4a
a = ½

fx = 3(x-½ /2) + 4(½)
= 3(x-½ /2) + 2

f(1) = 3(1-½ /2) + 2
= ¾ + 2
= ¾ + 8/4
= 11/4
= 2¾
= 2,75