Q. Solve the equation for all values of x.∣4x+9∣=5xAnswer: x=
Consider Two Cases: We have the equation ∣4x+9∣=5x. To solve this, we need to consider two cases because the absolute value function outputs the same value for both the positive and negative versions of its input.
Case 1: Non-Negative Expression: Case 1: The expression inside the absolute value is non-negative. This means we can remove the absolute value without changing the sign.So, we have 4x+9=5x.Now, we solve for x.Subtract 4x from both sides to get 9=x.
Case 2: Negative Expression: Case 2: The expression inside the absolute value is negative. This means we need to take the negative of the inside expression when removing the absolute value.So, we have −(4x+9)=5x.Now, we solve for x.Distribute the negative sign to get −4x−9=5x.Add 4x to both sides to get −9=9x.Divide both sides by 9 to get −1=x.
Find Potential Solutions: We have found two potential solutions for x: x=9 from Case 1 and x=−1 from Case 2. However, we must check these solutions to ensure they satisfy the original equation.
Check x=9: Check x=9 in the original equation ∣4x+9∣=5x.Substitute x with 9 to get ∣4(9)+9∣=5(9).Calculate the left side: ∣36+9∣=∣45∣=45.Calculate the right side: 5(9)=45.Since both sides are equal, x=9 is a solution.
Check x=−1: Check x=−1 in the original equation ∣4x+9∣=5x. Substitute x with −1 to get ∣4(−1)+9∣=5(−1). Calculate the left side: ∣−4+9∣=∣5∣=5. Calculate the right side: 5(−1)=−5. Since both sides are not equal, x=−1 is not a solution.
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