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PLEASE HELP ME!!! 17 pts!! Which system of linear inequalities has the point (2, 1) in its solution set?

User Soju
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1 Answer

4 votes

Explanation:

The system of Linear equation is x + 2y ≤ 4 and 2x - y > 0

Explanation:

Given: Point ( 2 , 1 )

To find: System of Linear Inequalities which contain given point in

its solution set

There are 2 lines passing through point ( 2 , 1 )

So first we find the equation of both lines

Equation of line using Two-Point form is given by,

(y-y_1)=\frac{y_2-y_1}{x_2-x_1}(x-x_1)(y−y1)=x2−x1y2−y1(x−x1)

Equation of line 1 passing through ( 0 , 2 ) & ( 4 , 0 )

(y-2)=\frac{0-2}{4-0}(x-0)(y−2)=4−00−2(x−0)

(y-2)=\frac{-2}{4}x(y−2)=4−2x

(y-2)=\frac{-x}{2}(y−2)=2−x

y=\frac{-x}{2}+2y=2−x+2

y+\frac{x}{2}=2y+2x=2

x+2y=4x+2y=4 ....... (1)

Equation line 2 passing through ( 0 , 0 ) & ( 2 , 1 )

(y-0)=\frac{0-2}{0-1}(x-0)(y−0)=0−10−2(x−0)

y=\frac{-2}{-1}xy=−1−2x

y=2xy=2x

2x-y=02x−y=0 ....... (2)

Now from given graph is clear line 1 contain the given point and area shaded by it is toward origin then we have less than equal sign,

⇒ x + 2y ≤ 4

Line 2 is dotted line. So, it does not contain the given point and area shaded by it is toward 4th quadrant then we have greater than sign in it.

⇒ 2x - y > 0

Therefore, The system of Linear equation is x + 2y ≤ 4 and 2x - y > 0

User Tomahaug
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