What is the graph of the system of equations y …

Mathematics Questions

What is the graph of the system y = –2x + 3 and 2x + 4y = –8?

Short Answer

The solution involves understanding two equations: y = -2x + 3 and rearranging 2x + 4y = -8 to find y. By substituting y from the first equation into the second, you find x = 3.33, and the y-intercepts are calculated as 3 for the first equation and -24 for the second, aiding in graphing.

Step-by-Step Solution

Step 1: Understand the Equations

Begin by examining the two equations provided. The first equation is y = -2x + 3, which represents a linear function. The second equation, 2x + 4y = -8, can also be rearranged to express y in terms of x. Understanding these equations is essential before attempting to graph them.

Step 2: Substitute and Solve

Next, substitute the expression for y from the first equation into the second equation. This means replacing y in 2x + 4y = -8 with -2x + 3. The substitution leads to:

  • 2x + 4(-2x + 3) = -8
  • Upon simplifying, get 2x – 8x + 12 = -8.
  • Combine like terms to find x, resulting in x = 3.33.

Step 3: Find the y-intercepts

Once you have the value for x, substitute it back into either original equation to find the y-value. Additionally, calculate the y-intercepts for both equations:

  • For the first equation: y-intercept = 3.
  • For the second equation: rearranging gives y-intercept = -24.
  • This information, along with the coordinate, will help in graphing the equations.

Related Concepts

Linear Function

A function that can be represented by a straight line when graphed on a cartesian plane, generally expressed in the form y = mx + b, where m is the slope and b is the y-intercept.

Substitution

A mathematical technique where a variable is replaced with an equivalent expression in order to solve equations or simplify them.

Y-Intercept

The point where a line crosses the y-axis, represented by the coordinates (0, y), which indicates the value of y when x is zero.

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