|3x+8|=20; -4
Basically that 4 is asking whether that is a possible solution to the problem. I tried to solve it and the two solutions I got were -28/3 and 4. So I got that -4 is not a solution but if someone could check for me and make sure I didn't mess up my signs that would be great. It just seems kinda funny that i got the right number but not the correct sign.
3x+8 = 20 --> x = +4
-3x - 8 = 20 --> x = -28/3
So I agree with you
To determine if -4 is a solution to the equation |3x + 8| = 20, you need to substitute -4 into the equation and check if it satisfies the equation.
Start by substituting -4 for x in the equation:
|3(-4) + 8| = 20
Simplify the equation by performing the operations:
|-12 + 8| = 20
|-4| = 20
Evaluate the absolute value of -4:
4 = 20
Since 4 is not equal to 20, the equation is not satisfied when x = -4.
Now, let's check the two other solutions you obtained: -28/3 and 4.
For x = -28/3:
|3(-28/3) + 8| = 20
Simplify the equation:
|-28 + 8| = 20
|-20| = 20
Evaluate the absolute value of -20:
20 = 20
Since 20 is equal to 20, the equation is satisfied when x = -28/3.
For x = 4:
|3(4) + 8| = 20
Simplify the equation:
|12 + 8| = 20
|20| = 20
Evaluate the absolute value of 20:
20 = 20
Since 20 is equal to 20, the equation is also satisfied when x = 4.
Therefore, after rechecking the solutions, you were correct that -4 is not a solution to the equation. The correct solutions are x = -28/3 and x = 4.