30% decrease
175 divided by 250 = 0.7
1 - 0.7 = 0.3
0.3 = 30%
Answer:
Part A is 34
Part B is 2
Step-by-step explanation:
This question did provide some clues to answer this question. Every week, the area covered by the algae is multiplied by 2^1.
To find the area cover increase by the algae per day, the exponent should be divided by 7 since there are 7 days in a week. Hence, every day, the area covered by the algae multiplies by 2^(1/7). In other words, 1 day after the algae was spotted, the area is 12.5 * 2^(1/7), which answers part B.
10 days after the algae was spotted, the area covered by the algae is 12.5 * 2^[(1/7)*10] = 33.6475... , which rounds up to 34 and answers part A.
Answer:
Step-by-step explanation:
1 ) k²-8k = 0
k(k-8)=0
k = 0 or k=8
2) a²+5a=0
a(a+5) = 0
a=0 or a = - 5
3 ) 6n²+5n-25=0
delta = b²-4ac b =5 and a = 6 and c= - 25
delta = 5²-4(6)(-25) = 625 = 25²
n 1 = (-5+25)/12 = 20/12 = 5/3
n 2 = (-5-25)/12 = - 30/12 = -5/2
same method for 4) and 5)
