18.9 rounded is 19
5.2 rounded is 5
19 * 5 = 95
Step-by-step explanation:
100% = 33,000 ft
1% = 100%/100 = 33000/100 = 330 ft
6% = 1% × 6 = 330 × 6 = 1980 ft
that means the plane has to go down 1980 ft to
33,000 - 1980 = 31,020 ft
and then it goes up by 5000 ft :
31,020 + 5000 = 36,020 ft
that is the final altitude.
Completing the square
alrighty
minus 31 both sides
x²+12x=-31
take 1/2 of the linear coefient and square it
12 is the linear coefient
12/2=6, (6)²=36
add that to both sides
x²+12x+36=36-31
factor perfect square trinomial
(x+6)²=5
square root both sides, remember to take positive and negative root
x+6=+/-√5
so what you want to write is
x+6=√5 and
x+6=-√5
the solutions
minus 6 both sides
x=-6+√5 and -6-√5
The answer to this question is A. 120°
