Bonsoir,
il suffit de remplacer x par la valeur donné et calculer.
1/ f(x) = 5x² - 4x + 3
f(2) = 5*2² - 4*2 + 3
f(2) = 5*4 - 8 + 3
f(2) = 20 - 8 + 3
f(2) = 15
f(-3) = 5*(-3)² - 4*(-3) + 3
f(-3) = 5*9 - (-12) + 3
f(-3) = 45 + 12 + 3
f(-3) = 60
f(2/3) = 5*(2/3)² - 4*(2/3) + 3
f(2/3) = 5*(4/9) - (8/3) + 3
f(2/3) = 20/9 - 8/3 + 3
f(2/3) = 20/9 - 24/9 + 27/9
f(2/3) = 23/9
f(0) = 5*0² - 4*0 + 3
f(0) = 3
f(1.4) = 5*(1.4)² - 4*(1.4) + 3
f(1.4) = 5*(1.96) - 5.6 + 3
f(1.4) = 9.8 - 5.6 + 3
f(1.4) = 7.2
