[180 – (100 – 40)]} =150

1,5 đ

= 150: {360: [180 – (4.25 – 8.5)]}

0,5

=150: {360: [180 – (100 – 40)]}

=150: {360: [180 – 60]}

=150: {360: 120}

= 150 : 3 = 50

b/ 4.(x – 12) = 60

0,25

x – 12 = 60 : 4

x – 12 = 15

x = 15 + 12

x = 27