Multiply Sum & Difference of Two Quantities
Algebra Help: Section 2.17
Learn to multiply the sum and difference of two quantities, with algebra.
Find the product of the sum and difference of two quantities.
The sum of two quantities multiplied by their difference gives a result still more simple than the square of a binomial.
1. Multiply a + b
by
a - b
Sum a + b
Difference a - b
_____________
a2 + ab
- ab - b2
_____________
a2 - b2
ANALYSIS -
Multiplying by the usual process, we find in adding
partial products,
that +ab with -ab
equals zero. The product is simply
a2 - b2.
Since a and b
may represent any two quantities whatever, the form
of this product embodies a general truth.
RULE - From the square of the greater quantity, subtract the square of the less.
NOTE - The term or quantity having the minus sign in the difference, is supposed to be the less.
Page 49-50
Page 49-50
Help with Algebra Homework
Free tutorials provide math help for math problems. Tutorials start with algebra 1. Algebra tutorials include word problems related to algebra topics, as they're introduced. See the menu, above for algebra math equations, and explanation, by section.
Windows algebra games, designed to help with classwork, coming soon!
Windows games, in progress, work with this set of free tutorials, modified
from the public domain text book titled,
New Elementary Algebra
containing the rudiments of the science for schools and academies.
By Horation N Robinison, LL. D. Ivison, Blakeman & Company, Publishers, New York and Chicago.
