SOLUTION: I am having trouble understanding how the answer was arived at on the following problem: 5X^2Y^2Z^3-X^2Y WHERE X=-2, Y=5, Z=-1 Here is my work 5*-2^2*5^2*-1^3--2^2*5 =500 -

Algebra ->  Expressions-with-variables -> SOLUTION: I am having trouble understanding how the answer was arived at on the following problem: 5X^2Y^2Z^3-X^2Y WHERE X=-2, Y=5, Z=-1 Here is my work 5*-2^2*5^2*-1^3--2^2*5 =500 -      Log On


   

Question 6173: I am having trouble understanding how the answer was arived at on the following problem:
5X^2Y^2Z^3-X^2Y WHERE X=-2, Y=5, Z=-1
Here is my work
5*-2^2*5^2*-1^3--2^2*5
=500 - (-)20
=520
The answer from my test was -520. How is this negative?

Found 2 solutions by ichudov, guapa:
Answer by ichudov(507) About Me  (Show Source):
You can put this solution on YOUR website!
Start with 5X%5E2%2AY%5E2%2AZ%5E3-X%5E2%2AY
them REPLACE X with -2, Y with 5, Z with -1:
+5%2A%28-2%29%5E2%2A5%5E2%2A%28-1%29%5E3+-+%28-2%29%5E2%2A5
Solved by pluggable solver: EXPLAIN simplification of an expression
Your Result:


YOUR ANSWER


  • Graphical form: 5%2A%28-2%29%5E2%2A5%5E2%2A%28-1%29%5E3-%28-2%29%5E2%2A5 simplifies to -520
  • Text form: 5*(-2)^2*5^2*(-1)^3-(-2)^2*5 simplifies to -520
  • Cartoon (animation) form: simplify_cartoon%28+5%2A%28-2%29%5E2%2A5%5E2%2A%28-1%29%5E3-%28-2%29%5E2%2A5+%29
    For tutors: simplify_cartoon( 5*(-2)^2*5^2*(-1)^3-(-2)^2*5 )
  • If you have a website, here's a link to this solution.

DETAILED EXPLANATION

Look at .
Replace constants in factor: highlight_red%28+%28-2%29+%29,highlight_red%28+2+%29 with highlight_green%28+4+%29
It becomes 5%2Ahighlight_green%28+4+%29%2A5%5E2%2A%28-1%29%5E3-%28-2%29%5E2%2A5.
Look at 5%2A4%2Ahighlight_red%28+5+%29%5Ehighlight_red%28+2+%29%2A%28-1%29%5E3-%28-2%29%5E2%2A5.
Replace constants in factor: highlight_red%28+5+%29,highlight_red%28+2+%29 with highlight_green%28+25+%29
It becomes 5%2A4%2Ahighlight_green%28+25+%29%2A%28-1%29%5E3-%28-2%29%5E2%2A5.
Look at 5%2A4%2A25%2Ahighlight_red%28+%28-1%29+%29%5Ehighlight_red%28+3+%29-%28-2%29%5E2%2A5.
Replace constants in factor: highlight_red%28+%28-1%29+%29,highlight_red%28+3+%29 with highlight_green%28+-1+%29
It becomes 5%2A4%2A25%2Ahighlight_green%28+-1+%29-%28-2%29%5E2%2A5.
Look at 5%2A4%2A25%2A-1-highlight_red%28+%28-2%29+%29%5Ehighlight_red%28+2+%29%2A5.
Replace constants in factor: highlight_red%28+%28-2%29+%29,highlight_red%28+2+%29 with highlight_green%28+4+%29
It becomes 5%2A4%2A25%2A-1-highlight_green%28+4+%29%2A5.
Look at highlight_red%28+5%2A4%2A25%2A-1+%29-highlight_red%28+4%2A5+%29.
Replace constants in expression: highlight_red%28+5%2A4%2A25%2A-1+%29,highlight_red%28+-4%2A5+%29 with highlight_green%28+-520+%29
It becomes highlight_green%28+-520+%29.
Look at highlight_red%28+-520+%29.
Removed extra sign in front of -520
It becomes -highlight_green%28+520+%29.
Result: -520

Universal Simplifier and Solver


Done!

Answer by guapa(62) About Me  (Show Source):
You can put this solution on YOUR website!
Let me split it up and compute the variables first.
x%5E2 = %28-2%29%28-2%29=4 to multiply 2 negative signs equals a positive.
y%5E2 = %285%29%285%29=25
z%5E3 = %28-1%29%28-1%29%28-1%29=-1 as a tip to remember: if the number of negatie signs to multiply is an odd number (here 3) then the answer is negative.
y = 5
Now let's substitute the variables for the computed values.
5%284%29%2825%29%28-1%29-%284%29%285%29 and we get
-500-20 which equals to
-520
Hope this helps