Bonsoir,
a)-3 * 5/4/15/6 + 5/1/2
= - 15/4 : 15/6 + 5/12
= - 15/4 x 6/15 + 5/12
= - 90/60 + (5 x 5) / (12 x 5)
= - 90/60 + 25/60
= - 65/60
= (5 x - 13) / (5 x 12)
= - 13/12
b) (3+2/5) : (3-4/10
)
= [(3 x 5) / (1 x 5) + 2/5] : [(3 x 10) / (1 x 10) - 4/10]
= (15/5 + 2/5) : (30/10 - 4/10)
= 17/5 : 26/10
= 17/5 x 10/26
= 170/130
= (10 x 17) / (10 x 13)
= 17/13
c) (3/2-15/8*6/27) : (5/12+66/12*4/33)
= [3/2 - 90/216) : (5/12 + 264/396)
= [(3 x 6) / (2 x 6) - (18 x 5) / (18 x 12)] : [5/12 + (33 x 8) / (33 x 12)]
= (18/12 - 90/12) : (5/12 + 8/12)
= -72/12 : 13/12
= - 72/12 x 12/13
= - 936/156
= (156 x 6) / (156 x 1)
= 6
