Question

$s = - 70 - 3t + t ^{2} \\ s = 4 - 5t + t ^{2}$

Answer 1

$s= -b \frac{+}{-}  \sqrt{}b^{2}-4ac/2a$

s= -70-3t+t²

s=-(-3) +-√(-3)² - 4.1. (-70)/2.1

s= 3+- √9+280/2

s= 3+-√289/2

s= 3+-17/2

s'= 3+17/2 = 20/2 = 10

s''= 3-17/2 = -14/2 = -7

s= 4-5t+t²

s= -(-5) +- √(-5)²-4.1.4/2.1

s= 5+- √25-16/2

s= 5+- √9/2

s= 5+-3/2

s'= 5+3/2 = 8/2 = 4

s''= 5-3/2 = 2/2 = 1