Respuesta :

Answer:

a=5 or a=15, b=15 or b=5

Step-by-step explanation:

b=20-a

a(20-a)=75

20a-[tex]a^{2}[/tex] -75=0

-[tex]a^{2}[/tex]+20a-75=0

[tex]a^{2}[/tex]-20a+75=0

(a-5)(a-15)=0

a-5=0 or a-15=0

a=5 or a=15

b=15 or b=5

(:

Answer:

Step-by-step explanation:

 a + b = 20

Sum of roots = 20

ab = 75

Product of roots = 75

x² - (a +b) x + ab = 0

x² - 20x + 75 = 0

Sum = coefficient of x = -20

Product = 75

Factors = 15 , 5    {15*5 = 75  & 15 +5 = 20}

x² - 15x - 5x + 75 = 0  {Rewrite the middle term}

x(x - 15) - 5(x - 15) = 0

(x - 15) (x - 5)=0

x - 15 = 0    ; x -5 = 0

x = 15        ; x = 5

a = 15  ;  b= 5