2b. (15i – 14j + 13k) + (–30i – 45j + 51k)
= 15i – 14j + 13k – 30i – 45j + 51k
= 15i – 30i – 14j – 45j + 13k + 51k
= –15i – 59j + 64k
2c. (3x – 17y + 35z) + (4x + 23y – 9z)
= 3x – 17y + 35z + 4x + 23y – 9z
= 3x + 4x – 17y + 23y + 35z – 9z
= 7x + 6y + 26z
3. Tentukan hasil pengurangan bentuk aljabar berikut
a. (42n + 35m + 7) − (−50m − 20n + 9) = ...