SOLUTION: (5r-2)(6r-4)

Algebra ->  Test -> SOLUTION: (5r-2)(6r-4)      Log On


   

Question 678903: (5r-2)(6r-4)
Answer by jim_thompson5910(35256) About Me  (Show Source):
You can put this solution on YOUR website!

%285r-2%29%286r-4%29 Start with the given expression.


Now let's FOIL the expression.


Remember, when you FOIL an expression, you follow this procedure:


%28highlight%285r%29-2%29%28highlight%286r%29-4%29 Multiply the First terms:%285%2Ar%29%2A%286%2Ar%29=30%2Ar%5E2.


%28highlight%285r%29-2%29%286r%2Bhighlight%28-4%29%29 Multiply the Outer terms:%285%2Ar%29%2A%28-4%29=-20%2Ar.


%285r%2Bhighlight%28-2%29%29%28highlight%286r%29-4%29 Multiply the Inner terms:%28-2%29%2A%286%2Ar%29=-12%2Ar.


%285r%2Bhighlight%28-2%29%29%286r%2Bhighlight%28-4%29%29 Multiply the Last terms:%28-2%29%2A%28-4%29=8.


---------------------------------------------------
So we have the terms: 30%2Ar%5E2, -20%2Ar, -12%2Ar, 8


30%2Ar%5E2-20%2Ar-12%2Ar%2B8 Now add every term listed above to make a single expression.


30r%5E2-32r%2B8 Now combine like terms.


So %285r-2%29%286r-4%29 FOILs to 30r%5E2-32r%2B8.


In other words, %285r-2%29%286r-4%29=30r%5E2-32r%2B8.