Answer: x = 4.2
Explanation: If we're asked to solve for <em>x</em> in the equation x + 1.5 = 7.5, what we're really being asked to do is get <em>x</em> by itself on one side of the equation.
So if we take a look at the left side of our equation, notice that 1.5 is being added to <em>x</em> so in order to get <em>x</em> by itself, we must subtract 1.5 from the left side of the equation. Now remember your first rule of solving equations. If we subtract 1.5 from the left side of the equation, we must also subtract 1.5 from the right side of the equation.
So on the left side our +1.5 and -1.5 cancel out and we're simply left with <em>x</em>. On the right side of the equation,
5.7 - 1.5 simplifies to 4.2 so our answer is <em>x = 4.2</em>.
The nice thing about solving equations is that you can always check your answer by plugging it back in to the original equation.
So here, we're gonna plug a 4.2 back in for <em>x</em> in the original equation and we get (4.2) + 1.5 = 5.7.
Since 4.2 + 1.5 = 5.7 is a true statement, our answer checks and we know that it's right.
