Cherries cost $2/lb. Grapes cost $0.50/lb. You can spend no more than $2 on fruit, and you need at least 2 lb in all.

Create a graph showing the amount of each fruit you can buy.

Give the coordinates of of linear inequalities in two variables.
2x+ y ≤ 4
y≥ -2x-1

Give the coordinates of the system of linear inequalities in two variables.
x+y ≥6
2x-y≤5

Give the coordinates of the solution of the system of linear inequalities.
y < -2x - 3
y > x + 3

1 answer

Let's break down each of your requests step by step.

1. Graphing the Fruit Purchase Problem

Variables:

  • Let \( x \) be the weight of cherries (in lbs).
  • Let \( y \) be the weight of grapes (in lbs).

Inequalities:

  1. Budget constraint: \( 2x + 0.5y \leq 2 \)
  2. Weight constraint: \( x + y \geq 2 \)
  3. Non-negativity constraints: \( x \geq 0, y \geq 0 \)

Rearranging the inequality:

  1. From \( 2x + 0.5y \leq 2 \): Rearranging gives \( y \leq 4 - 4x \).
  2. From \( x + y \geq 2 \): Rearranging gives \( y \geq 2 - x \).

2. Coordinates of the first set of Linear Inequalities

The inequalities provided are:

  1. \( 2x + y \leq 4 \)
  2. \( y \geq -2x - 1 \)

To find the points of intersection:

  • Set \( 2x + y = 4 \) and \( y = -2x - 1 \) to find where they intersect.

Substituting \( -2x - 1 \) into the first equation:

\[ 2x + (-2x - 1) = 4 \] \[ -1 = 4 \quad \text{(not possible)} \]

So, they do not intersect, but we can find their intercepts:

  • For \( 2x + y = 4 \):

    • \( x \)-intercept: \( (2, 0) \)
    • \( y \)-intercept: \( (0, 4) \)
  • For \( y = -2x - 1 \):

    • \( x \)-intercept: \( (-0.5, 0) \)
    • \( y \)-intercept: \( (0, -1) \)

3. Coordinates of the second system of Linear Inequalities

The inequalities provided are:

  1. \( x + y \geq 6 \)
  2. \( 2x - y \leq 5 \)

To find the points of intersection:

  • Set \( x + y = 6 \) and \( 2x - y = 5 \) to find the intersection.

Substituting \( y = 6 - x \) into the second equation:

\[ 2x - (6 - x) = 5 \] \[ 3x - 6 = 5 \] \[ 3x = 11 \implies x = \frac{11}{3} \]

Now plug \( x \) back to find \( y \):

\[ y = 6 - \frac{11}{3} = \frac{18}{3} - \frac{11}{3} = \frac{7}{3} \]

Coordinates:

  • Intersection point: \( \left(\frac{11}{3}, \frac{7}{3}\right) \)

Other intercepts can be calculated similarly for each inequality.

4. Coordinates of the solution of the third system of Linear Inequalities

The inequalities provided are:

  1. \( y < -2x - 3 \)
  2. \( y > x + 3 \)

To find the points of intersection:

  • Set \( y = -2x - 3 \) and \( y = x + 3 \).

Setting them equal:

\[ -2x - 3 = x + 3 \] \[ -3 - 3 = 3x \] \[ -6 = 3x \implies x = -2 \]

Now plug \( x \) back to find \( y \):

\[ y = -2(-2) - 3 = 4 - 3 = 1 \quad \text{or} \quad y = -2 + 3 = 1 \]

Coordinates:

  • Intersection point: \( (-2, 1) \)

Summary of Coordinates:

  1. For Cherries and Grapes: Represented by inequalities, calculate points based on constraints.
  2. First set: Intercepts found: \( (2, 0), (0, 4), (-0.5, 0), (0, -1) \).
  3. Second set: Intersection \( \left(\frac{11}{3}, \frac{7}{3}\right) \).
  4. Third set: Intersection \( (-2, 1) \).

You can plot these points and lines on a graph to visualize the feasible regions.