Yes, they are equivalent. Another equivalent fraction would be any fraction that equals to 1. Eg. 9/9
Answer:
2.9 years
Step-by-step explanation:
Given that :
Half-life t1/2 = 9 years
Initial mass = I = 70 grams
A = final mass = 56 grams
t = time taken to reach final amount
Using the exponential half life relation :
A = I(0.5)^t/t1/2
56 = 70(0.5)^t/9
56/70 = 0.5^t/9
0.8 = 0.5^t/9
Log 0.8 = log 0.5^t/9
−0.096910 = −0.301029 * t/9
t/9 = 0.096910 / 0.301029
t/9 = 0.3219291
t = 0.3219291 * 9
t = 2.8973619
t = 2.9 years
{(2, 3), (1, 5), (2, 7)} - NOT because 2->3 and 2->7
{(11, 9), (11, 5), (9, 3)} - NOT because 11->9 and 11->5
{(3, 8), (0, 8), (3, -2)}
- NOT because 3->8 and 3->-2
{(-1, 5), (-2, 6), (-3, 7)} - YES
The first one! It is using the distributive or associative property!
Answer:

Step-by-step explanation:
