Write an equation representing the following verbal sentence, and solve the equation. Let [tex] x [/tex] represent the unknown.

When [tex] \frac{5}{2} [/tex] of a number is subtracted from 18, the result is 3. Find the number.



Answer :

Sure, let's solve the problem step-by-step.

First, we need to represent the verbal sentence as a mathematical equation. The sentence states: "When [tex]\(\frac{5}{2}\)[/tex] of a number is subtracted from 18, the result is 3."

1. Let [tex]\( x \)[/tex] represent the unknown number.

2. According to the problem, [tex]\(\frac{5}{2}\)[/tex] of the number [tex]\( x \)[/tex] is subtracted from 18. This can be written as:

[tex]\[ 18 - \frac{5}{2}x = 3 \][/tex]

Next, we need to solve this equation for [tex]\( x \)[/tex]. Here are the steps:

3. Start by isolating the term involving [tex]\( x \)[/tex]. To do this, subtract 18 from both sides of the equation:

[tex]\[ 18 - \frac{5}{2}x - 18 = 3 - 18 \][/tex]

Simplifying this, we get:

[tex]\[ -\frac{5}{2}x = -15 \][/tex]

4. To solve for [tex]\( x \)[/tex], we need to get rid of the coefficient [tex]\(-\frac{5}{2}\)[/tex]. Multiply both sides of the equation by the reciprocal of [tex]\(-\frac{5}{2}\)[/tex], which is [tex]\(-\frac{2}{5}\)[/tex]:

[tex]\[ x = (-15) \times \left(-\frac{2}{5}\right) \][/tex]

5. Now, perform the multiplication:

[tex]\[ x = \frac{30}{5} \][/tex]

Simplifying the fraction, we find:

[tex]\[ x = 6 \][/tex]

So, the number is [tex]\( 6 \)[/tex].