Question

Sendo f(x) = 4x - 5, determine o valor de
imagem abaixo

Answer 1

f(x) = 4x - 5

f(12) = 4 . 12 - 5

f(12) = 48 - 5

f(12) = 43

f(7) = 4 . 7 - 5

f(7) = 28 - 5

f(7) = 23

f(4) = 4 . 4 - 5

f(4) = 16 - 5

f(4) = 11

f(3) = 4 . 3 - 5

f(3) = 12 - 5

f(3) = 7

[f(12) - f(7)]/[f(4) - f(3)] = (43 - 23)/(11 - 7)

[f(12) - f(7)]/[f(4) - f(3)] = 20/4

[f(12) - f(7)]/[f(4) - f(3)] = 5

Resposta: 5

Answer 2

Explicação passo-a-passo:

$\sf \bullet~~f(3)$

$\sf f(x)=4x-5$

$\sf f(3)=4\cdot3-5$

$\sf f(3)=12-5$

$\sf \green{f(3)=7}$

$\sf \bullet~~f(4)$

$\sf f(x)=4x-5$

$\sf f(4)=4\cdot4-5$

$\sf f(4)=16-5$

$\sf \green{f(4)=11}$

$\sf \bullet~~f(7)$

$\sf f(x)=4x-5$

$\sf f(7)=4\cdot7-5$

$\sf f(7)=28-5$

$\sf \green{f(7)=23}$

$\sf \bullet~~f(12)$

$\sf f(x)=4x-5$

$\sf f(12)=4\cdot12-5$

$\sf f(12)=48-5$

$\sf \green{f(12)=43}$

Logo:

$\sf \dfrac{f(12)-f(7)}{f(4)-f(3)}=\dfrac{43-23}{11-7}$

$\sf \dfrac{f(12)-f(7)}{f(4)-f(3)}=\dfrac{20}{4}$

$\sf \large\red{\dfrac{f(12)-f(7)}{f(4)-f(3)}=5}$