Mohon di bantu menjawab..dan dikasih cara mengerjakannya ya tolong

Nomor 1
= 1/2 + 3/8 – 3/4 (samakan penyebut)
= [(1×12)/(2×12)] + [(3×3)/(8×3)] – [(3×6)/(4×6)]
= 12/24 + 9/24 – 18/24
= 3/24

Nomor 2 (panjang total pita)
= 1/2 + 1/3 + 1/4
= 6/12 + 4/12 + 3/12
= 13/12
= 1 1/12

Nomor 3
6/7 – B + 1/3 = 5/14 (dikali -1)
-6/7 + B – 1/3 = -5/14
B = -5/14 + 6/7 + 1/3
B = -15/42 + 36/42 + 14/3
B = 35/42 (bagi 7)
B = 5/6