Mohon bantuannya dari no 1 sampe no 5

1. -3¼ + 3(8/15)
= -13/4 + 24/15
= -13/4 + 8/5
= -45/20 + 32/20
= -13/20

2. -12 : -3 = 4

3. 3^(3 – 1 – 7) = 3^-5 = 1/3^5= 1/243

4. a^28 x b^-21 = a^28 / b^21

5. 4√6 – 5√6 + 2√6 = √6