If anyone can check my work for me that would be greatly appreciated I'm having trouble.
Evaluate the expression foe the given value of the variable.
|-4b-8|+|-1-b^2|+2b^3 ; b=-2
I got 1 for my answer
-4(-2)-8-1+2^2+2(-2)
8-8-1+2^2-4
-1+2^2-4
1
|-4(-2)-8| + |-1-(-2)^2| + 2(-2)^3
|-4(-2)-8| + |-1-4| + 2(-8)
|8-8| + |-1-4| - 16
0+5-16
-11
Can somebody please help me with solving this and show steps if they can. Solve the equation. Check for extraneous solutions. 9|9-8X|=2X+3
For my answer I got X=-1
I divided by 9 on both sides I got 8X=2X-6
Then I divided by 6 on both sides and got X=-1
If you went from
9|9-8x|=2x+3
to
8x=2x-6
you certainly did not divide by 9 (on BOTH sides)!
All absolute-value problems have two possibilities.
First,
9(9-8x)=2x+3
81-72x = 2x+3
78 = 74x
x = 39/37
Second,
9(9-8x) = -(2x+3)
81-72x = -2x-3
70x = 84
x = 6/5
To check your work, let's go step by step through the evaluation of the expression.
The original expression is: |-4b-8| + |-1-b^2| + 2b^3.
Given value of the variable: b = -2
Step 1: Evaluate |-4b-8| using the given value of b.
|-4b-8| = |-4(-2) - 8| = |-8 + 8| = |0| = 0
Step 2: Evaluate |-1-b^2| using the given value of b.
|-1-b^2| = |-1-(-2)^2| = |-1-4| = |-5| = 5
Step 3: Evaluate 2b^3 using the given value of b.
2b^3 = 2(-2)^3 = 2(-8) = -16
Now, let's substitute these values back into the original expression to find the final answer:
0 + 5 + (-16) = -11
Therefore, the correct answer for the given expression when b = -2 is -11, not 1.