Question

Johnny says that when he substitutes x in the equation with -12 the answer is -42. If this is the equation:

-5x + 18 = -42

can you verify that Johnny is correct?

Answer 1

Answer:

The answer is actually x=12

Step-by-step explanation:

The reason behind that is because you are to move all the terms that don't contain x to the right side and then you solve!

Answer 2

Answer:

Johny's answer isn't correct.

Step-by-step explanation:

As per the provided information in the given question, we have :

• When John substitutes the value of x as –12 in the equation, he gets the answer –42.
• Equation :: –5x + 18 = –42

We are asked to verify that Johny is correct or not.

In order to verify the answer, we need to solve the equation by substituting the value of x with –12. We'll be using transposition method to solve the equation.

★ Transposition Method :

• This is the method used to solve a linear equation having variables and constants.

• In this method, we transpose the values from R.H.S to L.H.S and vice-versa and changes its sign while transposing to find the value of the unknown value.

Now, let's verify the answer:

L.H.S :

➝ –5x + 18

• Substitute the value of x which is –12.

➝ –5(–12) + 18

Multiply –5 with –12. We know that when negative number is multiplied with another negative number we get the answer in positive. So,

➝ 60 + 18

➝ 78

R.H.S :

➝ –42

Comparing L.H.S and R.H.S, we get ,

⇒ L.H.S ≠ R.H.S

$\therefore$ Johny isn't correct.