Answer:
(negative 7 x + 4)(negative 7 x minus 4)
Step-by-step explanation:
Consider two real numbers a and b. A difference of squares involving a and b is usually given as;
The difference of the two squares above can be factored to yield;
This implies that in order to have the difference of squares we must have a product involving the difference and the sum of the numbers.
The expression;
(negative 7 x + 4)(negative 7 x minus 4) can also be written as ( 4 - 7x) ( -4 - 7x)
( 4 - 7x) ( -4 - 7x) = ( 4 - 7x) (-1( 4 + 7x)) = -1 *( 4 - 7x) ( 4 + 7x)
Expanding the last expression yields;
-1 (16 + 28x -28x - 49x^2) = -1 (16 - 49x^2) = 49x^2 - 16 which is in deed a difference of squares