SOLUTION: find the product (10+7x)^2 a)100+140x+49x^2 b)100+49x^2 c)100+140x+7x^2 d)100x^2+140x+49

Algebra ->  Equations -> SOLUTION: find the product (10+7x)^2 a)100+140x+49x^2 b)100+49x^2 c)100+140x+7x^2 d)100x^2+140x+49      Log On


   

Question 147739: find the product
(10+7x)^2
a)100+140x+49x^2
b)100+49x^2
c)100+140x+7x^2
d)100x^2+140x+49
Answer by jim_thompson5910(35256) About Me  (Show Source):
You can put this solution on YOUR website!

%2810%2B7x%29%5E2 Start with the given expression.


%2810%2B7x%29%2810%2B7x%29 Expand. Remember something like x%5E2=x%2Ax.


Now let's FOIL the expression.


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


%28highlight%2810%29%2B7x%29%28highlight%2810%29%2B7x%29 Multiply the First terms:%2810%29%2A%2810%29=100.


%28highlight%2810%29%2B7x%29%2810%2Bhighlight%287x%29%29 Multiply the Outer terms:%2810%29%2A%287%2Ax%29=70%2Ax.


%2810%2Bhighlight%287x%29%29%28highlight%2810%29%2B7x%29 Multiply the Inner terms:%287%2Ax%29%2A%2810%29=70%2Ax.


%2810%2Bhighlight%287x%29%29%2810%2Bhighlight%287x%29%29 Multiply the Last terms:%287%2Ax%29%2A%287%2Ax%29=49%2Ax%5E2.


100%2B70%2Ax%2B70%2Ax%2B49%2Ax%5E2 Now collect every term to make a single expression.


100%2B140%2Ax%2B49%2Ax%5E2 Now combine like terms.


So %2810%2B7x%29%5E2 FOILS to 100%2B140%2Ax%2B49%2Ax%5E2.


In other words, %2810%2B7x%29%5E2=100%2B140%2Ax%2B49%2Ax%5E2.