Answer:
49x²-16 = (7x - 4)(7x + 4)
Step-by-step explanation:
Your "49×2-16" is incorrect; did you mean "49x^2-16" or "49x²-16?"
This last expression is the difference of two squares.
The formula for that is a² - b² = (a - b)(a + b), and so your 49x²-16 factors as follows:
49x²-16 = (7x - 4)(7x + 4)
