6. One variable only so pretty straightforward.
length-x+4
width-x
x+x+4=80
2x=76
x=38
x+4=42
answer: length 42cm and width 38cm
7. Another money problem!
n-# of nickels
q-# of quarters
n=3+q
0.05n+0.25q=2.85
Substitution works like a charm!
0.05(3+q)+0.25q=2.85
0.15+0.05q+0.25q=2.85
0.3q=2.7
q=9
n=3+q
n=3+9
n=12
answer: 9 nickels and 12 quarters
8. One variable situation again.
Ann's money-2b+9
Betty's money-b
b+2b+9=60
3b=51
b=17
2b+9=43
answer: Ann has $43 and Betty has $17.
9. # of red m&m's-x+1
# of blue m&m's-x
x+1+x=13
x=6
x+1=7
answer: 6 blue and 7 red m&m's
10. a-number of adult tickets
s-number of student tickets
a+s=785 ----> a=785-s
5a+2s=3280
5(785-s)+2s=3280
-3s=-645
s=215
a+s=785
a+215=785
a=570
answer: 215 children tickets and 570 adult tickets
Answer:
Selena is correct because she simplified correctly and then evaluated correctly after substituting the values for the variables.
I did this lesson i asked my teacher to help me but i did this problem on my own so i hope its right :)
Step-by-step explanation:
B because B is the answer
Answer:
194
Step-by-step explanation:
<h3>
Answer: Choice H) 2</h3>
=============================================
Explanation:
Recall that the pythagorean trig identity is 
If we were to isolate sine, then,
We don't have to worry about the plus minus because sine is positive when 0 < x < pi/2.
Through similar calculations, 
Cosine is also positive in this quadrant.
-------------
So,
Therefore,
is an identity as long as 0 < x < pi/2
