|
Question 176981: I would really appreciate if you could look over these problems and tell me if they are correct. It has been over 30 plus years since I done any algebra and I have a test coming up.
1. 5> 2x+4 or 11 greater than 5x+4 Answer x< 1/2
2. Elimination Method
5r -3s=2
3r+5s=26 Answer 44/17
3. Translate to an algebraic expression
The product of 44% and some number Answer .44x=y
Use y to represent some number
4. System as consistent or inconsistent and as dependent or independent
9x-9y=63
9y-9x=63
What is the solution of the system of equation?
A. Infinitely many solution Answer (A)
B. Point
C. No solution
5. Soybeans meal is 14% protein: cornmeal is 7%. How many pounds of each should be mix together in order to get 280lb mixture that is 10% protein?
How many pounds of cornmeal should be mixture? Answer 160
How many pounds of soybeans meal should be mixture? Answer 120
6. Find the slope and the y-intercept f(x)-3x-2
The slope is 3
The y-intercept is (0,-2)
7. Substitution method
7x+5y=-32
X=2-4y Answer (2,-6)
Answer by solver91311(24713)   (Show Source):
You can put this solution on YOUR website! 1. 
but
11 greater than 5x+4
2.
5r -3s=2
3r+5s=26 Answer 44/17
 is true, but that's only half of the problem. Now you have to solve for s. Since you were able to come up with the correct value for r, I assume you know the process, so just repeat the process but eliminate r instead of s. You should come up with 
3. Translate to an algebraic expression
The product of 44% and some number Answer .44x=y
Use y to represent some number
The problem says to translate to an algebraic expression, not an equation, and it says to use y to represent 'some number' So your expression should be .44y.
4. System as consistent or inconsistent and as dependent or independent
9x-9y=63
9y-9x=63
What is the solution of the system of equation?
A. Infinitely many solution Answer (A)
B. Point
C. No solution
Put both of these equations into slope-intercept form and you will see the answer directly.
Divide by 9 (both equations, both sides)
Add -x to both sides of the first one, and x to both sides of the second one.
Now multiply the first equation by -1:
Now you should be able to see that you have two parallel lines (because the slopes are equal), but with different y-intercepts (one is -7 and the other is 7). That means you have two distinct parallel lines. Since parallel lines never intersect, there is no solution, hence Answer C. Answer A, infinite solutions is the case where the two equations actually represent the same line. If you had solved this one using the elimination method, you would have come up with the absurdity that  . A No Solution system always eliminates to an absurdity like that. An infinite solution system always eliminates to a trivial identity, like  .
5. You did this one correctly.
6. You wrote: Find the slope and the y-intercept f(x)-3x-2. I presume you meant f(x) = 3x - 2, in which case your answer is correct.
7. Very close but no cigar. You actually have the correct numbers but  and  , so your solution set is (-6, 2) rather than (2, -6).
|
|
|
| |
