Question

Please help me please tell me the answer AND explain why it's the answer​

Answer 1

Hi Student!

This question is fairly simply and the main goal of this question is to determine whether x = 3 is a solution of the expression that was provided or not. The first step that we take is to plug in all of the values or in this case we input the value 3 for everywhere we see x in the equation. The next step is to simplify the expression on both sides and finally compare the expression to see if it evaluates to true. If it evaluates to true then x = 3 is a solution but if it evaluates to false then x = 3 isn't a solution.

Plug in the values

• 
  `5x^2 < 40`

• 
  `5(3)^2 < 40`

Simplify the expression

• 
  `5(3*3) < 40`

• 
  `5(9) < 40`

• 
  `45 < 40`

Looking at the final expression that was simplified, we can see that it states that 45 is less than 40 when we know that is not the case. Therefore, this would evaluate to the expression being false and x = 3 not being a solution of the expression that was given in the problem statement.

Answer 2

NO

Explanation:

If x = 3

then

5x² = 5×(3)² = 5 × 9 = 45

and 45 > 40

Therefore

3 is not a solution to the inequality 5x² < 40.