Question

Yang pinter matematika bantuin plisss

Answer 1

Nomor 2
f(x) = 2/5 (3x+4) = 6x/5 + 8/5
f^-1(x) = (x - (8/5)) / (6/5) = ((5x/5) - (8/5)) × 5/6 = (5x-8) / 6
jadi, f^-1(x) = (5x-8) / 6
selanjutnya tinggal x di ganti

nomor 3
f(x) = (2x/5) + 14/5
f^-1(x) = (x- (14/5)) / (2/5)
f^-1(a) = (a-(14/5)) / (2/5)
3 = (a - (14/5)) × 5/2
3 = (5a/5 - (14/5)) × 5/2
3 × 10 = 5(5a-14)
30 = 25a - 70
30+70 = 25a
a = 100/25
a = 4