X|-1|0|1|2

Question

Y|-2|1|4|7

What is the rule for the function shown in the tablet?

A)y=⅓x+1
B)y=3x+1
C)y=⅓x
D)y=½x+1

I think the answer is B...am I wrong?...please help I have no clue on how to solve these kind of problems

Answer 1

Straight-line equations is the "slope-intercept" form:

y = m * x + b

x = - 1 , y = - 2

y = m * x + b

- 2 = m * ( - 1 ) + b

- 2 = - m + b Add 2 to both sides

- 2 + 2 = - m + b + 2

0 = - m + b + 2 Add m to both sides

0 + m = - m + b + 2 + m

m = b + 2

x = 0 , y = 1

y = m * x + b

1 = m * 0 + b

1 = b

b = 1

m = b + 2

m = 1 + 2

m = 3

y = m * x + b

y = 3 x + 1

x = 1 , y = 4

y = 3 x + 1

y = 3 * 1 + 1

y = 3 + 1

y = 4

x = 2 , y = 7

y = 3 x + 1

y = 3 * 2 + 1

y = 6 + 1

y = 7