Answer:
(2n - 7) - 10
Step-by-step explanation:
(2n - 7) represents "difference of 2 times a number and 7"
- 10 represents "10 less"
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
Here you go, hope it helps!
Not on your list, but an easy way is
.. a) swap coefficients of x and y, negating one. (Now you have 2x -3y.)
.. b) set any constant term to zero (now you have 2x -3y = 0)
.. c) translate the line to the point (5, 2) by substituting x ⇒ x-5, y⇒ y-2
2(x -5) -3(y -2) = 0
The way you've been taught, selection C is the proper choice.
It is A because I did 100 times 200 and I got 200,000