Question

Solve the equation using mental math.

$- 10a = 130$

Short answer

The solution of the equation is a = – 13

Step-by-step solution

Apply the concept of equation: 

An equation is a mathematical statement that two expressions are equal. The solution of an equation is the value that when substituted for the variable makes the equation a true statement.

Example: 3x + 5 = 14 is an equation, in which 3x+5 and 14 are two expressions separated by an ‘’equal’’ sign.

What are the steps to solve an equation? 

Step 1: Simplify each side of the equation by removing parenthesis and combining the like terms.

Step 2: Use addition or subtraction to isolate the variable term on one side (preferably in the left side).

Step 3: Use Multiplication or Division to solve for the variable.

Step 3: Solve the equation using mental math. -10a=130

Now solving the equation $-10a=130$with proper steps

$\begin{array}{l}-10a=130\\ \frac{-10a}{-10}=\frac{130}{-10}\text{Dividebothsidesby}-10\\ a=-13\end{array}$

Solution of the equation is $a=-13$