H(t)=-16t^2+24
so i have to find how long (in seconds) it will take a tool to fall to the ground from a height of 24 feet. i am using the equation h(t)=-16t^2+24 to find it but i'm not sure how to solve it or where to even get started! any would be great you!

If 10 men take 18 days to mow 60 acres of grass, how long will 15 men take to mow 80 acres?

Worth 100 points need the answers asap first row -x^2 2x^2 (x/2)^2 x^2 x is less than 2 x is greater than 2 x is less than or equal to 2 x is greater than or equal to 2 second row -5 -5/2 4 5 •2 is less than x& x is less than 4 •2 is less than or equal to x & x is less than or equal to 4 •2 is less than or equal to x& x is less than 4 •2 is less than x& x is less than or equal to 4

Simplify (4x^2 - 8xy + 2y^2) - (9x^2 - 4xy - 7y^2) a. -5x^2 + 4xy + 9y^2 b. -5x^2 - 4xy + 9y^2 c. -5x^2 + 12xy + 4y^2 d. -5x^2 - 4xy - 5y^2