Proportional Line Math Example 4

Follow the full solution, then compare it with the other examples linked below.

medium

y = 3x + 2

a proportional relationship? Why or why not?

1
When $x = 0$ : $y = 2 \neq 0$ . The line does not pass through the origin.
2
Proportional relationships require $y = kx$ (no constant term), so this is not proportional.

Answer

Not proportional (it has a

y

-intercept of 2).

A proportional relationship

y = kx

always passes through

(0, 0)

. The equation

y = 3x + 2

is linear but not proportional because of the

+2

term.

About Proportional Line

A straight line that passes through the origin, representing a proportional relationship of the form $y = kx$ with constant ratio $k$ .

A recipe uses 3 cups of flour for every 2 cups of sugar. Write the relationship as [formula] and fin

Does the table represent a proportional relationship? [formula]: 2, 4, 6; [formula]: 5, 10, 15.

If [formula], find [formula] when [formula].