Jawabanmu

2014-08-08T07:57:01+07:00
*kelompokan variabel yg sejenis kemudian dijumlahkan/dikurangkan
1. ( 15i + 14j + 13k ) + (-30i - 45 j + 5k)
= 15i-10i +14j-15j +13k+5k
= -5i - j +18k

2.
(-3m + 4n- 6 ) + ( 7n - 8m + 10 )
= -3m-8m +4n+7n -6+10
= -11m + 11n +4

3. 
(5a + 7b - 3c) + (11a-12b + 13c)
= 5a+11a +7b-12b -3c+13c
= 16a -5b +10c

semoga membantu :-)
2014-08-08T07:59:54+07:00
1. ( 15i + 14j + 13k ) + (-30i - 45 j + 5k)
    = 15i + 14j + 13k - 30i - 45j + 5k
    = 15i - 30i + 14j - 45j + 13k + 5k
    = -15i - 31j + 18k
2. 
(-3m + 4n- 6 ) + ( 7n - 8m + 10 )
    = -3m + 4n - 6 + 7n - 8m+ 10
    = -3m - 8m + 4n + 7n -6 + 10
    = -11m + 11n + 4
3. 
(5a + 7b - 3c) + (11a-12b + 13c)
    = 5a + 7b - 3c + 11a - 12b + 13c
    = 5a + 11a + 7b - 12b - 3c + 13c
    = 16a - 5b + 10c
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