Question

Dada a função f(x)= - x/2 + 9, calcule a)f(x)=3 b)f (- 1/4) c)f (x)=6 d) f(8)

Answer 1

a) -x/2+9 = 3 (tira o mmc) -x+18=6 logo x=12

b)-(-1/4)/2 + 9 = (1/4)/2 +9 = (simplifica 1/4 por 2 e o 2 por 2)
1/2+9 = (tira o mmc) 1+18/2 = 19/2

c) -x/2+9= 6 (tira o mmc)
-x+18=12, logo x=6

d) -8/2+9 = -4+9, logo x=5

Answer 2

 f(x)= - x/2 + 9, calcule

a)f(x)=3 => - x + 9 = 3 => -x +18 = 6(-1)=> x-18= -6=>x = -6+18==> x = 12
                     2
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b)f (- 1/4) => - (-1): 2 + 9 = 1.1+9= 1 + 9 => 1+72 ==> 73
                          4   1          4 2       8     1         8            8
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c)f (x)=6 => - x + 9 = 6 => -x +18 = 12(-1)=> x-18= -12=>x = -12+18=> x = 6
                      2
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d) f(8) => - 8 + 9 = - 4 + 9 => 5
                  2