Learn to solve equations like "x + 3 = 9" or "y - 5 = 8". Based on our understanding of the balance beam model, we know that we always have to do the same thing to both sides of an equation to keep it …

There are lots of strategies we can use to solve equations. Let's explore some different ways to solve equations and inequalities. We'll also see what it takes for an equation to have no solution, or infinite …

In this lesson, we learn how to solve simple equations with one unknown variable. To find the unknown, we remove extra numbers by doing the opposite operation on both sides of the equation.

Learn how to add and subtract negative numbers. The problems solved in this video are 2 - 3 = -1 and -2 - 3 = -5 and -2 + 3 = 1 and 2 - (-3) = 5 and -2 - (-3). Created by Sal Khan.

Finding a missing angle Since the sum of the interior angles in a triangle is always 180 ∘ , we can use an equation to find the measure of a missing angle.

The quadratic formula helps us solve any quadratic equation. First, we bring the equation to the form ax²+bx+c=0, where a, b, and c are coefficients. Then, we plug these coefficients in the formula: (-b±√ …

Adding like terms is a fundamental concept in algebra. Coefficients are the numbers in front of variables, and they can be added when the variables are the same. For example, 2x + 3x equals 5x. When …

Because of the law of conservation of mass, balancing chemical equations gives a more accurate representation on what's happening in a reaction. The accuracy of the ratios of moles is important in …

We would have introduced an X on the right hand side of the equation, but what if we could add something that's equivalent to negative X plus three Y that does not introduce the X variable?

What you've written is just an expression, not an equation. You can't solve for x because there's nothing to solve. You can simplify the expression, but it will still have different values for different values of x.