You can only simplify the expression, because it doesn't equal anything. If you simplify it it would be:
4n-1 + 3n-7
4n+3n + -1-7
7n-8
Answer:
The measures of the angles at its corners are 
Step-by-step explanation:
see the attached figure to better understand the problem
step 1
Find the measure of angle A
Applying the law of cosines
![cos(A)= [215^{2}+125^{2}-185^{2}]/(2(215)(125))](https://tex.z-dn.net/?f=cos%28A%29%3D%20%5B215%5E%7B2%7D%2B125%5E%7B2%7D-185%5E%7B2%7D%5D%2F%282%28215%29%28125%29%29)
step 2
Find the measure of angle B
Applying the law of cosines
![cos(B)= [215^{2}+185^{2}-125^{2}]/(2(215)(185))](https://tex.z-dn.net/?f=cos%28B%29%3D%20%5B215%5E%7B2%7D%2B185%5E%7B2%7D-125%5E%7B2%7D%5D%2F%282%28215%29%28185%29%29)
step 3
Find the measure of angle C
Applying the law of cosines
![cos(C)= [125^{2}+185^{2}-215^{2}]/(2(125)(185))](https://tex.z-dn.net/?f=cos%28C%29%3D%20%5B125%5E%7B2%7D%2B185%5E%7B2%7D-215%5E%7B2%7D%5D%2F%282%28125%29%28185%29%29)
A) x/y = 2/3
B) x + y = 105
Solving Equation A for y
A) y = 1.5x
Substituting A into B
B) x + 1.5x = 105
2.5x = 105
x = 42
y = 63
Answer: The height of the building is 6.49 meters.
Step-by-step explanation:
This can be translated to:
"A building projects a 7.5 m shadow, while a tree with a height of 1.6 m projects a shadow of 1.85 m.
Which is the height of the building?"
We can conclude that the ratio between the projected shadow is and the actual height is constant for both objects, this means that if H is the height of the building, we need to have:
(height of the building)/(shadow of the building) = (height of the tree)/(shadow of the tree)
H/7.5m = 1.6m/1.85m
H = (1.6m/1.85m)*7.5m = 6.49m
The height of the building is 6.49 meters.
Answer: 16
Solution:
1) Use letters to identify the variables:
Number of trumpets: t
Number of clarinets: c
2) Translate each statement into algebraic (mathematical) language.
2.1) Sold a total of 27 used trumpets and clarinets
=> t + c = 27
2.2) Trumpets cost $149 and clarinets cost $99
Total cost of the trumpets: 149t
Total cost of clarinets: 99c
Total cost = 149t + 99c
2.3) Total sales were $3223
=> 149t + 99c = 3223.
3) State the system of equations:
Equation (1) t + c = 27
Equation (2) 149t + 99c = 3223
4) Solve the system of equations:
4.1) Multiply equation 1 by 149:
=> 149t + 149c = 4023
4.2) Subtract the equation (2) from the equation obtained in 4.1
=> 149c - 99c = 4023 - 3223
=> 50c = 800
=> c = 800 / 50 = 16
5) Verify the solution:
From equation (1) t = 27 - 16 = 11
Total cost = 149*11 + 99*16 = 3223
Now you have a verified answer: they sold 16 clarinets
