Hands-on math!

Equation

An equation is a math sentence that says that 2 things are equal. An equation always has an equal (=) sign. The thing or things that are on the left side of the equal sign are equal to the things on the right side of the equal sign. Here are a few equations:

    X = Y + 5
    A = B - 4
    Z = 3 A
    C =  D  (circumference of a circle)
    A = W H  (area of a rectangle with width W and height H)
    E = M C2 (Einstein's famous equation!)

In the first equation, if Y is 2, then X must be 2 + 5 or 7 to make the equation true. In the second equation, if B is 10, then A must be 6 to make the equation true. In the third equation, the number next to the letter means multiply the value of the variable represented by "A" by 3. So if A is 4, then Z must be 12 to make the third equation true.

To learn more about solving equations, see how to solve an equation.

Now here's a problem for you:

In the first equation, if Y were 10, what would X be?