Question

sendo m1 e m2 as raizes da equaçao 3x²-20x+25=0 determinie 5(m1+m2)- m1m2

Answer 1

3x² - 20x + 25 = 0

Δ = b² - 4ac
Δ = 400 - 4.25.3
Δ = 400 - 300
Δ = 100

x = (-b+-√Δ)/2a
x = (20 +-√100)/2.3
x = (20+-10)/6
x = (10+-5)/3

x' = (10+5)/3 = 15/3 = 5
x" = (10-5)/3 = 5/3

5(m1+m2) - m1.m2
5(5+5/3) - 5.5/3
5[(15+5)/3] - 25/3
5.20/3 - 25/3
100/3 - 25/3
75/3
25