bonjour
f( 3000) = 1 250 et f ( 4 500 ) = 1400
( 1400 - 1250) / ( 4 500 - 3 000)
= 150/1500 = 0.1
ax = 0.1 x
f ( 3000) = 1 250
0.1 * 3000 + b = 1 250
b = 1 250 - 300 = 950
f ( x) = 0.1 x + 950
f ( 4 500 ) = 4 500 * 0.1 + 950 = 1400
f ( 5 000 ) = 5 000 * 0.1 + 950 = 1 450