Which expression is equvilant to(4-3i)+(-2+10i)?

a. 9i
b. -9i
c. 2+7i
d. 2-13i

The size of a certain cell is 2.5*10^-9m. another cell is 1.5*10^3 times larger. how large is the larger cell in scientific notation?

What are the solutions of the equation? 16x^2 + 24x + 5 = 5 a. 1/4, 5/4 b. -1/4, -5/4 c. -1/4, 5/4 d. 1/4 , -5/4

After t seconds, a ball tossed in the air from the ground level reaches a height of h feet given by the equation h = 144t-16t^2. after how many seconds will the ball hit the ground before rebounding?