20 POINTS!!!!! URGENT!!!!!

A= 7/15 - 2/15 x 9/4
= 7/15 - 2x9/15x4
= 7/15 - 18/60
= 7x4/15x4 - 18/60
= 28/60- 18/60
= 10/60
= 10/60 : 10
= 1/6

bonsoir

A = 7/15 - 2/15 x 9/4
a = 7/15  - 18/ 60
a = 28/60 - 18/60
a = 10/60
a = 1/6

b = 75 x 10⁴ sur 2 x 10²
b = 37.5  x 10 ²
b = 3.75 x 10 ³
b = 3750