Set h to 640 and solve for t:
640 = -490t^2 + 1120t
Subtract 640 from both sides:
-490t^2 + 1120t - 640 = 0
The formula to solve a quadratic equation is:
x = -b -/+ sqrtroot (b^2-4ac)/(2a) where a = -490, b = 1120 and c = -640
Solve:
x = -1120 -/+ sqrtroot (1120^2-4(-490)(-640) )/ 2(-490)
x = 8/7 = 1.1428 = 1.14
Time was 1.14 seconds
Answer:
It is not correct, the answer is 15
Step-by-step explanation:
They forgot the rule of PEMDAS, and accidentally subtracted before they multiplied. It should've gone
(25+3) - 7 x 3 + (2x4)
28-7x3+8
28-21+8
Since it's minus 21, that means it's negative, so -21+8=13
28-13=15
Answer:
1
Step-by-step explanation:
x-7=-5x-1
x-(-5x)-7=-1
x+5x-7=-1
6x-7=-1
6x=-1+7
6x=6
x=6/6
x=1
