/*! This file is auto-generated */ .wp-block-button__link{color:#fff;background-color:#32373c;border-radius:9999px;box-shadow:none;text-decoration:none;padding:calc(.667em + 2px) calc(1.333em + 2px);font-size:1.125em}.wp-block-file__button{background:#32373c;color:#fff;text-decoration:none} Problem 5 Find the intersection of the two... [FREE SOLUTION] | 91Ó°ÊÓ

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Find the intersection of the two lines. $$2 x-y=6, x+2 y=8$$

Short Answer

Expert verified
The lines \(2x - y = 6\) and \(x + 2y = 8\) intersect at the point \((4, 2)\).

Step by step solution

01

Title

Start by solving the first equation \(2x - y = 6\) for \(x\). Add \(y\) to both sides of the equation to isolate \(x\), resulting in \(x = \frac{6 + y}{2}\)
02

Title

Substitute the expression for \(x\) from step 1 into the second equation \(x + 2y = 8\). This gives \(\frac{6 + y}{2} + 2y = 8\). Multiply each term by \(2\) to eliminate the fraction, leading to \(6 + y + 4y = 16\)
03

Title

Combine like terms and solve for \(y\). This results in \(5y = 10\), so \(y = 2\)
04

Title

Substitute \(y = 2\) into the first equation \(2x - y = 6\). Simplifying the equation, we get \(2x - 2 = 6\). Solving for \(x\) gives \(x = 4\)
05

Final Step Title

Our solution is \((x, y) = (4, 2)\), which is the point where the two lines intersect.

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Key Concepts

These are the key concepts you need to understand to accurately answer the question.

Linear Equations
Linear equations are mathematical statements that describe a straight line when plotted on a coordinate grid. These equations typically take the form \(ax + by = c\), where \(a\), \(b\), and \(c\) are constants, and \(x\) and \(y\) are variables.
Each solution to a linear equation represents a point on the line. To solve linear equations, you often use algebraic methods such as substitution or elimination.

In the problem, we have two linear equations: \(2x - y = 6\) and \(x + 2y = 8\). To find their intersection, we need to determine the point where these lines cross or, in other words, the \((x, y)\) that satisfies both equations.
It's essential to understand that in a pair of linear equations, the intercepts and slope of the lines can tell you a lot about their behavior. If two lines have different slopes, they will intersect at one point.
Solving Systems of Equations
When you have two or more equations working together, you have what's called a "system of equations." Solving these systems is all about finding values for the variables that satisfy each equation simultaneously.

There are several methods to solve systems of equations, with substitution and elimination being common pathways. In substitution, you solve one equation for one variable and then substitute this expression into another equation. This is exactly what the exercise showcases, where \(x\) is isolated in the first equation and substituted into the other.

In elimination, you'd add or subtract equations to cancel out one of the variables. This transforms a system of equations into a simpler form you can solve. Both methods lead you to the same solution, and it's often helpful to chose based on which seems easier with the given equations.
  • Substitution: Replace variables using another equation.
  • Elimination: Align terms to cancel a variable out.
Understanding these techniques will enhance your ability to handle more complex systems in the future.
Coordinate Geometry
In coordinate geometry, you use points plotted on a graph to understand geometric principles through the combination of algebra and geometry.
Points are positioned using coordinate pairs \((x, y)\), and lines are often represented through equations. In this context, your focus is primarily on understanding how lines behave, represented by their equations, intercepts, and intersections.

In our exercise, finding the intersection of two lines means determining where these two lines meet on a graph, which corresponds to a solution of the system of equations. This point represents the only set of \((x, y)\) values that will work for both of the given equations simultaneously.
  • Understand that the graph is a visual representation of all solutions a line can have.
  • The intersection is the single point where all involved lines agree, solution-wise.
Knowing how to navigate coordinate geometry empowers you to visually and analytically solve geometry and algebra problems, paving the way for future mathematical topics.

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Most popular questions from this chapter

Minimize \(P=16 x+10 y\) subject to the following constraints. $$\left\\{\begin{array}{l} y \geq 2 x \\ x \geq 5 \\ x \geq 0 \\ y \geq 0 \end{array}\right.$$

$$\begin{aligned}&\text { If } A=\left[\begin{array}{cc}4 a+5 & -1 \\\\-4 & -7\end{array}\right] \text { and } B=\left[\begin{array}{rr}7 & 0 \\\\-4 & -8\end{array}\right], \text { for what }\\\&\text { value(s) of } a \text { does } 2 B-3 A=\left[\begin{array}{ll}2 & 3 \\\4 & 5\end{array}\right] ?\end{aligned}$$

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The total revenue generated by a film comes from two sources: box-office ticket sales and the sale of merchandise associated with the film. It is estimated that for a very popular film such as Spiderman or Harry Potter, the revenue from the sale of merchandise is four times the revenue from ticket sales. Assume this is true for the film Spiderman, which grossed a total of \(\$ 3\) billion. Find the revenue from ticket sales and the revenue from the sale of merchandise.

Sarah can't afford to spend more than \(\$ 90\) per month on transportation to and from work. The bus fare is only \(\$ 1.50\) one way, but it takes Sarah 1 hour and 15 minutes to get to work by bus. If she drives the 15 -mile round trip, her one-way commuting time is reduced to 40 minutes, but it costs her S.40 per mile. If she works at least 20 days a month, how often does she have to drive in order to minimize her commuting time and keep within her monthly budget?

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