graphing linear inequalities: testing points for solutions

[sarah thorp]

Tell whether the ordered pair is a solution of the inequality.

1. y < 4x; (3, 0)

2. y > -x - 1; (2, -3)

3) y </= 4x - 2; (-1, 1)

 

[jwpaine]

Hey Sarah!

An inequality, means that the equation is "not" balanced.

You have an ordered pair (x,y) values.

If the equation was y < x than you can see that the "carrot" is bigger on the x side: thus x is greater.

Plug in the values in your ordered pair, and see if both sides of the equation match the direction of inequality.


Best of luck!

 

[Mrspi]

Re: graphing linear inequalities

Tell whether the ordered pair is a solution of the inequality.

1. y < 4x; (3, 0)

2. y > -x - 1; (2, -3)

3) y </= 4x - 2; (-1, 1)

An ordered pair is a solution to an equation or inequality if the equation or inequality is true when the coordinates of the ordered pair are substituted for the variables.

y < 4x means "the value of y is less than the value of 4 * x"

You've got the ordered pair (3, 0). Substitute 3 for x and 0 for y:

y < 4x
0 < 4*3

0 < 12

Is this true? No! So, the given point is NOT a solution of the inequality.

(By the way, in regards to a previous answer....I'd be very careful of responses involving a "carrot," which is a vegetable and not a mathematical symbol)

 

[morson]

Re: graphing linear inequalities

0 < 12

Is this true? No! So, the given point is NOT a solution of the inequality.

Since when was 0 not smaller than 12?