Ok she can buy 1 ten and 25 ones, 2 tens 15 ones, 3 tens 5 ones, and 35 ones. (Pretty sure)
Answer:

Step-by-step explanation:
Given the equation

Use distributive property:

Use commutative property to rewrite the equation:


Add 10 th both sides:

Subtract 

Divide by 13:

Answer:
t = 3 arc cos(h/7)/π
Step-by-step explanation:
The equation h=7cos(pi/3 t) models the (h) height in centimeters after (t) seconds of a weight attached to the end of a spring that has been stretched and released. To solve the equation for t we will solve the equation step by step:
h=7cos(pi/3 t)
Step 1)
Divide both sides by 7
h/7 = 7cos(pi/3 t)/7
Now the equation becomes h/7=cos(pi/3 t)
Step 2)
h/7=cos(pi/3 t)
Now apply inverse cosine function:
arc cos (h/7) = pi/3 t
Step 3)
t = 3 arc cos(h/7)/pi
Thus t = 3 arc cos(h/7)/pi ....
There are 19 people total, and groups of four are being asked of us. We can use the formula for permutations or combinations.
Permutations:

Combinations:

Where in both scenarios, there are <em>n</em> objects being chosen at <em>r</em> times.
19 P 4 is 93024
19 C 4 is 3876
It all depends on whether order matters with group placement; if it does, your answer is
93024, if not, then your answer is
3876.:)