Answer:
(2x + 7yj)(2x - 7yj)
Step-by-step explanation:
Both 4x^2 and 49y^2 are perfect squares, and
4x^2 + 49y^2 is the sum of two squares.
There is a formula for factoring the difference of two squares:
a^2 - b^2 = (a - b)(a + b) (all real numbers here), but unless imaginary numbers are allowed, there's no formula for factoring the sum of two squares.
If imaginary numbers are allowed, then a^2 + b^2 factors into
(a + jb)(a - jb).
Following this pattern, 4x^2 + 49y^2 factors into (2x + 7yj)(2x - 7yj)
a^2 + b^2 = (a + b)(a
