Answer:
Step-by-step explanation:
we will use distributive property to write an equivalent expression:
7(-2x)+7(6)
2.9 years
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
(8,5)
5x - 2y = 30
coordinates are (x,y) so you plug in 8 for x and solve for y
5(8) - 2y = 30
40 - 2y = 30
subtract 40 from both sides to isolate y
-2y = -10
divide both sides by -2 to isolate y
y = 5
