Help ASAP Select all the following that are quadratic equation.
( ) 5x^2+15x=0
( ) 6x-1=4x+7
( )x^2-4x=4x+7
( ) 2x-1=0
( ) 3x^2+5x-7=0
( ) x^3-2x^2+1=0

right answers only please do not waste my time cause 20 points are quite good

Lorne subtracted 6x3 – 2x + 3 from –3x3 + 5x2 + 4x – 7. use the drop-down menus to identify the steps lorne used to find the difference.

Mr and mrs smith buy tickets for themselves and their four children. the cost of an adult ticket is ? 6 more than the adult ticket. the total cost of the six tickets is ? 40.50 work out the cost of an adult ticket. in your working let c be the cost of the child ticket and a be the cost of the adult ticket.

5,600 x 10^3 = a) 560 b) 5,000,600 c) 5,600,000 d) 56,000