I also suggest using an app called photomath. It takes you through the steps of solving the equations and gives you the answer as well.
Answer:
D. -2x - 8
Step-by-step explanation:
1) Simplify 1/3(6x+15) to 6x+15/3
-6x+15/3 - 3
2) Factor out the common term 3.
-3(2x+5)/3 - 3
3) Cancel 3.
-(2x+5)-3
4) Remove parentheses.
-2x-5-3
5) Collect like terms.
-2x+(-5-3)
6) Simplify
-2x-8
When the firecracker hits the ground, H(t) = 0.0 = -16t^2 + 90t + 160 Using the quadratic formula,t = (-90 +- sqrt(90^2 - 4(-16)(160))) / 2(-16)t = -1.42 ort = 7.04
The negative time is extraneous. Therefore,t = 7.04 s.
Seven Seconds is your answer!
The product is 3.3333333333333 so less. hope this was helpfull
