Which equations are quadratic? Check all that apply.
A. 2x2 + 3 = 0
B. x3 – 7x+ 1 = 0
C. 4x2 + 8x = 0
D. 5x – 12 = 0
E. x2 + 2xy + 9 = 0
F. x2 + 2x + 7 = 0

The difference of two numbers is 40. find the numbers if 0.3 parts of one number is equal to 37.5% of the other one.

Mr. thompson took five of his children to the bowling alley the cost for children 12 and older is 350 the cost of four children under 12 inch to 25 he spent a total of 1625 how many of his children are 12 and order

What are the triple angle formulas? is it related to double angle identities?