Question

Determine a raiz da função afim y = -7x + 14: * a) 2 b) 4 c) 6 d) 8

Answer 1

Resposta:

y = -7x + 14

a) 2

y = -7 × 2 + 14

y = -14 + 14

y = 0

y = -7x + 14

0 = -7x + 14

7x = 14

x = 14/7

x = 2

y = -7x + 14

0 = -7 × 2 + 14

0 = 0

b) 4

y = -7x + 14

y = - 7 × 4 + 14

y = -28 + 14

y = -14

y = -7x + 14

-14 = - 7x + 14

-14 -14 = -7x

7x = 28

x = 28/7

x = 4

y = -7x + 14

-14 = - 7 × 4 + 14

-14 = -28 + 14

-14 = -14

c) 6

y = -7x + 14

y = - 7 × 6 + 14

y = -42 + 14

y = -28

y = -7x + 14

-28 = -7x + 14

7x = 14 + 28

7x = 42

x = 42/7

x = 6

y = -7x + 14

-28 = -7 × 6 + 14

-28 = -42 + 14

-28 = -28

d) 8

y = -7x + 14

y = -7 × 8 + 14

y = - 56 + 14

y = -42

y = -7x + 14

-42 = -7x + 14

7x = 14 + 42

7x = 56

x = 56/7

x = 8

y = -7x + 14

-42 = -7 × 8 + 14

-42 = -56 + 14

-42 = -42