1.
a.(5/12+7/12)*3/10
=1*3/10=3/10
b.(15/8-7/8)*6/9
=1*6/9=6/9
c.\(\dfrac{15\cdot4\cdot13\cdot4}{8\cdot13\cdot5\cdot12}\)=\(\dfrac{5\cdot3\cdot4\cdot4}{2\cdot4\cdot5\cdot3\cdot4}\)=\(\dfrac{1}{2}\)
d.\(\dfrac{6\cdot7\cdot8\cdot9}{2\cdot9\cdot2\cdot8\cdot2\cdot7\cdot2\cdot6}\)=\(\dfrac{1}{2\cdot2\cdot2\cdot2}\)=\(\dfrac{1}{16}\)
e.\(\dfrac{4\cdot5\cdot3\cdot9\cdot12\cdot2}{3\cdot12\cdot4\cdot2\cdot5}\)=9
1.
a.(5/12+7/12)*3/10
=1*3/10=3/10
b.(15/8-7/8)*6/9
=1*6/9=6/9
c.5⋅3⋅4⋅42⋅4⋅5⋅3⋅45⋅3⋅4⋅42⋅4⋅5⋅3⋅4=6⋅7⋅8⋅92⋅9⋅2⋅8⋅2⋅7⋅2⋅66⋅7⋅8⋅92⋅9⋅2⋅8⋅2⋅7⋅2⋅6=116116
e.