While one-step equations are all about solving the problem in a single step, two step equations are nothing but adding one more step and solving the problem in 2 steps. Here you need to follow 2 straight-forward steps where you need to simplify the equation in the first step by using the inverse of addition or subtraction.
In the next step, simplify the equation further by using the inverse of multiplication or division.
Let’s look at an example:
Solve 4x – 2 = 10
Now let’s add 2 to both sides of the equation, which becomes:
4x – 2 + 2 = 10 + 2
4x = 12
Now in the next step divide both sides by 4, which becomes:
Remember – solving two-step equations can be very simple as all you need to do is ensure whatever you do in one side of the equation, should also be done on the other side. Take for example the problem we solved above; we added 2 to both sides of the equation.
But we cannot add 2 on one side and then 3 on the other side. Similarly, we divided both sides by 4 and remember, we cannot use the same number on both sides, whether you are adding, subtracting, multiplying or dividing.
Ex 1: Solve 6x+2 = 20
First let’s subtract -2 to both sides of the equation, which gives us 6x +2 -2 = 20-2,
6x = 18
Now divide both sides by 6, which gives us the answer of:
In this problem, we notice the variable is on one side of the equation and the first step is to eliminate the number next to the variable. So we subtract by 2 on both sides and then divide using 6 on both sides to get the result.
Example 2: Solve -2b+5 = 15
So, let’s remove the number first and subtract -5 on both sides, which gives the result of:
-2b = 10
In the next step, divide both values by -2, which gives the result of:
b = -5
Example 3: Solve 4x – 10 = 40
Add 10 on both sides:
4x + 10 – 10 = 40 + 10
4x = 50
Divide by 4 on both sides.
4x/4 = 50/4
x = 12.5