SOLUTION: It's multiplying binomials mentally. The problem is (5x-3)(3x-8), the answer I got was 15x-31-24. I got it wrong though. Please help me, Thanks=)

Algebra ->  Polynomials-and-rational-expressions -> SOLUTION: It's multiplying binomials mentally. The problem is (5x-3)(3x-8), the answer I got was 15x-31-24. I got it wrong though. Please help me, Thanks=)      Log On


   

Question 147451This question is from textbook algebra
: It's multiplying binomials mentally. The problem is (5x-3)(3x-8), the answer I got was 15x-31-24. I got it wrong though. Please help me, Thanks=) This question is from textbook algebra

Answer by jim_thompson5910(35256) About Me  (Show Source):
You can put this solution on YOUR website!

%285x-3%29%283x-8%29 Start with the given expression.


Now let's FOIL the expression.


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


%28highlight%285x%29-3%29%28highlight%283x%29-8%29 Multiply the First terms:%285%2Ax%29%2A%283%2Ax%29=15%2Ax%5E2.


%28highlight%285x%29-3%29%283x%2Bhighlight%28-8%29%29 Multiply the Outer terms:%285%2Ax%29%2A%28-8%29=-40%2Ax.


%285x%2Bhighlight%28-3%29%29%28highlight%283x%29-8%29 Multiply the Inner terms:%28-3%29%2A%283%2Ax%29=-9%2Ax.


%285x%2Bhighlight%28-3%29%29%283x%2Bhighlight%28-8%29%29 Multiply the Last terms:%28-3%29%2A%28-8%29=24.


15%2Ax%5E2-40%2Ax-9%2Ax%2B24 Now collect every term to make a single expression.


15%2Ax%5E2-49%2Ax%2B24 Now combine like terms.


So %285x-3%29%283x-8%29 FOILS to 15%2Ax%5E2-49%2Ax%2B24.


In other words, %285x-3%29%283x-8%29=15%2Ax%5E2-49%2Ax%2B24.