Deandre bought 15 party hats priced at 3 for 0.65 and 56 noisemakers priced at 7 for 1.25. what was the total cost of the hats and noisemakers not including tax

Take 15 and divide it by 3 and you get 5. That's what you'll multiply 0.65 by. Divide 56 by 7 and you'll get 8. That's what you'll divide 1.25 by. 5 multiplied by 0.65 is 3.25. 8 multiplied by 1.25 is 10. Add 3.25 and 10 and you'll get 13.25.
The answer is $13.25.

9x² - 16 = (3x - 4) (3x + 4)
A      C

The value of ac together is 16(9x²) or 144x²

The value of B is zero, since there is no B (b is x, (note not x², but only 1 x))

hope this helps