b. 12 × (−7) + (−6) ÷ (−2)
c. −15 ÷ (−3) −7 × (−4)
d. [1 + 2 ÷ 3 × 4] × [9 × 7 (7 –8) ÷ (6 + 5)]
Jawab:
a. 5 × ( 15 −6)
Bentuk panjang: 5 × ( 15 −6) = 5 × 15 − 5 × 6
= 75 – 30
= 45
Bentuk pendek: 5 × (15 − 6) = 5 × (9)
= 45
b. 12 × (−7) + (−6) ÷ (−2)
12 × (−7) + (−6) ÷ (−2) = (12 × 7) + (-6/-2)
= 84 + 3
= 87
c. −15 ÷ (−3) − 7 × (−4)
−15 ÷ (−3) − 7 × (−4) = (−15/−3) − (7 × (−4))
= 5 − ( -28 ) = 5 + 28
= 33
d. [1 + 2 ÷ 3 × 4] × [9 × 7 (7 –8) ÷ (6 + 5)]
= [1 + 2 × 4/3] × [9 × 7 × (-1) : 11
= [3/3 + 8/3] × – 63 : 11
= [11/3] × – 63 : 11
= -21
Penjelasan 7 (7 – 8) sama artinya dengan 7 × (7 – 8)
a. Penyelesaian bentuk panjang:
7 × (7 – 8) = (7 × 7) – (7 × 8)
= 49 – 56
= – 7
b. Penyelesaian bentuk pendek, penjumlahan di dalam kurung diselesaikan dahulu.
7 × (7 – 8) = 7 × (7 – 8)
= 7 × ( – 1 )
= – 7