Question

Dada a função real f(x)=x²-5x+5, determine:
a)f(-5):
b) o valor de x tal que f(x)=5

Answer 1

A) f(5)=x²-5x+5

f(5)= 5² -5.5 +5

f(5)=25 - 25+5

f(5)= 5

B) f(x)=x²-5x+5=5

 f(x)= x²- 5x=5-5

f(x)= x² -5x=0

x(x-5)=0

x-5=0

x=5

Answer 2

a)

f(-5)= -(5^2)-5*-5+5

f(-5)= 25+25+5

f(-5)= 55

b) 5=(x^2)-5*x+5

5-5=(x^2)-5*x

0=(x^2)-5*x

5*x=x^2

x=5