Chapter 1.8, Problem 10P

Tell whether the given number is a solution of each equation.

$-4x+7=15;-2$

To determine

To determine whether the number $-2$ is a solution of the equation:

  $-4x+7=15$

Answer to Problem 10P

Yes, the number $-2$ is a solution of given equation.

Explanation of Solution

Given:

  $-4x+7=15$

Concept Used:

To check whether a number ‘ a’ is a solution of a equation substitute a for the variable and then check whether it make equation an identity, that is if both sides left and right become equal.

Calculation:

In order to determine whether the number $-2$ is a solution of the equation:

  $-4x+7=15$

Substitute $-2$ for x in given equation, as

  $\begin{array}{c}-4\left(-2\right)+7=15\\ \Rightarrow 8+7=15\\ \Rightarrow 15=15\end{array}$

Since, an identity $15=15$ is arrived. Thus, the number $-2$ satisfies the given equation.

Thus, the number $-2$ is a solution of given equation.