I pretty sure it is A I looked it up.
A half-life of the isotope is 15 days and at start its mass is 32 g.
A table:
t: m:
0 32 g
15 16 g
30 8 g
45 4 g
60 2 g
75 1 g
In the first column is used an arithmetic sequence ( a 1 = 0, d = 15 ).
In the second column is used a geometric sequence ( a 1 = 32, r = 1/2 )
Answer:
x=3
Step-by-step explanation:
This is a proportional equation:
Given: x/9=9/27
Cross-multiply: 27x=81
Divide: x=3
So x=3
Answer:
x+3
Step-by-step explanation:
combine like terms then simple math
The triangle that does not have the y angle, equate all of its angles to 180 degrees and solve for x. Once you solve for x, substitute that value to the angles in the other triangle, and then add them all up and equate it to 180 degrees to solve for y.