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Linear equation word problems
By Khan Academy
Learn how to solve a word problem by writing an equation to model the situation. In this video, we use the linear equation 210(t-5) = 41,790.
Linear equation word problems
By Khan Academy
Learn how to solve a word problem by writing an equation to model the situation. In this video, we use the linear equation 210(t-5) = 41,790.
Linear equation word problems
By Khan Academy
Learn how to solve a word problem by writing an equation to model the situation. In this video, we use the linear equation 210(t-5) = 41,790.
Adding using measurement problem
By Math mamoth
This lesson presents a measurement word problem that involves addition. A visual is used to write an equation and solve.
2.3 Quadratic Equations in One Variable Part 1
By Tammy B
Solve quadratic equations in one variable.
Solving Quadratic Equations in one Variable by Factoring
By Victoriamiles
Solve quadratic equations in one variable.
Finding One Variable Statistics With a Graphing Calculator
By YouTube (Firm)
This quick YouTube video from high school statistics teacher Roger W. Davis explains how to find one variable statistics using the TI-84 graphing calculator. The demonstration goes through three steps: entering the data, finding one variable statistics using the STAT menu, and interpreting the results. The data created includes mean, sum, median and more. Flash player is required to view this video, and the running time for the clip is 3:12.
Solving rational equations 2 | Polynomial and rational functions | Algebra II | Khan Academy
By Khan Academy
The instructor in this video (04:08) discusses how to solve rational equations using another problem. Sl Khan shows how to multiply to remove the fractions to make solving easier. He uses computer software for demonstration. The viewer may want to open the video to 'full screen' because the instructor has a lot of small writing on a black screen.
Reasoning with Equations and Inequalities
By Khan Academy
Sal solves the equation 4x^2+40x-300=0 by completing the square.265
Systems of Three Equations | MathHelp.com
By MathHelp.com
Here we’re asked to graph the following function and use the horizontal line test to determine if it has an inverse. And if so, find the inverse function and graph it. So let’s start by graphing the given function, f(x) = 2x – 4, and remember that f(x) is the same as y, so we can rewrite the function as y = 2x – 4. Now, we simply graph the line y = 2x – 4, which has a y-intercept of -4, and a slope of 2, or 2/1, so we go up 2 and over 1, plot a second point and graph our line, which we’ll call f(x). Next, we’re asked to use the horizontal line test to determine if the function has an inverse. Since there’s no way to draw a horizontal line that intersects more than one point on the function, the function does have an inverse. So we need to find the inverse and graph it. To find the inverse, we switch the x and the y in original function, y = 2x – 4, to get x = 2y – 4. Next, we solve for y, so we add 4 to both sides to get x + 4 = 2y, and divide both sides by 2 to get 1/2x + 2 = y. Next, let’s flip our equation so that y is on the left side, and we have y = 1/2x + 2. Finally, we replace y with the notation that we use for the inverse function of f, as shown here. And remember that we’re asked to graph the inverse as well, so we graph y = ½ x + 2. Our y-intercept is positive 2, and our slope is ½, so we go up one and over 2, plot a second point, graph the line, and label it as the inverse function of f. Notice that the graph of the inverse function is a reflection of the original function in the line y = x.
Adding and Subtracting Polynomials | MathHelp.com
By MathHelp.com
In this example, notice that each of our variables, x, y, and z, appears in all three equations. To solve this system, we use the addition method. In other words, let’s start with our first two equations, x + y + z = 4, and x – y + z = 2. Notice that if we add these equations together, the +y and –y will cancel out, and we have 2x + 2z = 6. So, in our new equation, 2x + 2z = 6, we’ve eliminated the variable y. Unfortunately, we still haven’t solved for any of our variables. However, if we can create another equation with just x and z in it, then we’ll have a system of equations in two variables, which we can use to solve for x and z. To create another equation with just x and z in it, we need to eliminate y. We can’t add the first and second equations together, because we’ve already done that. However, notice that if we add the first and third equations together, the first equation has a +y and the third equation has a –y, so we’ll be able to eliminate the y. So we have our first equation, x + y + z = 4, and our third equation, x – y – z = 0, and adding them together, notice that the +y – y cancels out, and, as a bonus, the +z – z also cancels out, so we have 2x = 4, and dividing both sides by 2, x = 2. Now, since we know that x = 2, notice that if we plug a 2 in for x in the equation that we created earlier, we can solve for z. And we have 2(2) + 2z = 6, or 4 + 2z = 6, and subtracting 4 from both sides, we have 2z = 2, and dividing both sides by 2, z = 1. So x = 2 and z = 1, and to find the value of y, we simply plug our values of x and z into any of the equations in the original system. Let’s use the first equation, x + y + z = 4. Since x = 2 and z = 1, we plug a 2 in for x and a 1 in for z, and we have 2 + y + 1 = 4, or 3 + y = 4, and subtracting 3 from both sides, y = 1. So x = 2, y = 1, and z = 1, and finally, we write our answer as the ordered triple, x, y, z, or (2, 1, 1).
Understanding inequalities and equations
By MathPlanetVideos
Margaret is paying $1,500 in rent for her apartment every month. Margaret won $12,000 in Vegas and wondering how many rent she can afford to pay with this winning?