Question

4) Determine a raiz ou zero das seguintes funções do primeiro grau:
a) y = -3x - 2
b) y = -5x+ 15
c) y = 7x
d) y=-x-1
e) y = 2/5 de x. + 1
f) y=-3/4x+2/5​

Answer 1

a) y = -3x - 2

-3x -2 = 0

3x = -2

x = -2/3

b) y = -5x+ 15

-5x + 15 = 0

5x = 15

x = 15/5

x = 3

c) y = 7x

7x = 0

x = 0

d) y=-x-1

-x - 1 = 0

x = -1

e) y = 2/5 de x. + 1

2x/5 + 1 = 0

2x/5 = -1

2x = -5

x = -5/2

f) y=-3/4x+2/5​

-3x/4 + 2/5 = 0

3x/4 = 2/5

3x = 2*4/5

x = 8/5*3

x = 8/15