Answer:
<u>y = 6 x=8</u>
Step-by-step explanation:
(3х + 5y = 54)-2 times by -2
6х +4y = 72
-6х + -10y = -108 now combine the equations
6х + 4y = 72
-6y = -36 now divide
y = 6
Plug 6 in 6х +4 * 6 = 72
x=8
8(51)
=8(50+1)
=(8*50)+(8*1)
=(8*5*10)+(8*1)
=400+8
=408
Answer:
16 mls of the 75% solution and 20 mls of the 0.57% solution.
Step-by-step explanation:
Set up a system of equations:
Let x = volume of 75% solution and y be volume of 57% solution
0.75x + 0.57y = 36*0.65
0.75x + 0.57y = 23.4.......(1)
x + y = 36.........(2)
From equation (2):
y = 36 - x
Substituting this into equation(1):
0.75x + (0.57(36 - x) = 23.4
0.75x + 20.52 - 0.57x = 23.4
0.18x = 23.40 - 20.52 = 2.88
x = 2.88/0.18
x = 16
so from equation (2): y = 36-16 = 20.
Answer:
Whether or not a given isotope is radioactive is a characteristic of that particular isotope. Some isotopes are stable indefinitely, while others are radioactive and decay through a characteristic form of emission. As time passes, less and less of the radioactive isotope will be present, and the level of radioactivity decreases. An interesting and useful aspect of radioactive decay is half-life, which is the amount of time it takes for one-half of a radioactive isotope to decay. The half-life of a specific radioactive isotope is constant; it is unaffected by coTnditions and is independent of the initial amount of that isotope.
