Answer:
Step-by-step explanation:
2nd one
Joel = j, Mark = m, Sandra = s
j + m + s = 120
m = 3j
j = 1/2 s --> s = 2j
plug in (substitute) each letter to make it in terms of only j: j + m + s = 120
j + 3j + 2j = 120
6j = 120
6j/6 = 120/6
j = 20
now plug in for the j & s equation:
s = 2j = 2(20) = 40
Therefore Sandra has 40 coins!
The rotational symmetry has more than one order of rotational symmetry the objects can fit itself within 360 degrees.
Answer:
14-2a
Step-by-step explanation:
Since 15 and 21 are not included: we will have
=15-2a-1
=14-2a
Answer:
<h2>It's not a function.</h2>
Step-by-step explanation:
A function is a process or a relation that associates each element x of a set X, to a single element y of another set Y.
We have:
{(3, -2), (1, 2), (-1, -4), (-1, 2)}
for x = -1 are two values of y = -4 and y = 2. Therefore this realtion is not a function.