Post # 1
I tutor an eighth grader (usually in reading and history), but he has a big Algebra test coming up and we are trying to do this problem…I know there is an algebraic way to figure out the answer, but I can’t remember. Can you help??
5x + 4y = 32
x + 6y = 22
Post # 5
- Wedding: March 2013 - Callanwolde Fine Arts Center
First you need to determine what the values of x and y are.
x+6y=22 therefore x=22-6y
Plug that back into the first equation: 5(22-6y)+4y=32
Solve for y:
Use y to solve for x: x=4. (roses)
Check your work using the other equation. The answer is then A
Post # 6
@mrshunnybunches: Ahhh I had that but then I put =32 for the second equation. D’oh this is why I am bad at math!! Thank you!
Post # 7
You wanted to know the process. Here it is:
You have two equations:
We now know that x=22-6y.
Substitute that in with your first equation:
Post # 9
Here is another one!! I don’t even know what equation to write. I thought the Pythagorean Theorem would work, but that gives the answer 7.2…
A ball rolls down a ramp with a slope of 2/3. At one point the ball is 10 feet high, and at another point the ball is 4 feet high, as shown in the diagram below.
[Insert right looking triangle here]
What is the horizontal distance [x], in feet, the ball traveled as it rolled down the ramp from 10 feet high to 4 feet high?
Edited for clarity, sorry about that! We’re going to work on this one on Wednesday…boy I feel dumb.
Post # 10
@peachacid: OK, I’m not 100% on this one. I googled the math problem to find the diagram, since I think this is actually really important.
We know the slope is 2/3. That means on a graph, it will be 2 up and 3 over. If the height of 2 points is 6 feet, then the length between each point must be 3 feet. So if the length the ball rolled is three points, the length must be 9 feet.
Sorry – I wasn’t great at graphing and using slope to solve problems!! I’m fairly sure that this is the right answer, but I’m sure there is a better way to find it!!
Post # 11
@peachacid: For the rolling ball problem, you’re going to want to use the equation for a line:
y = mx + b where m is the slope of the line (2/3) and b is where the line intersects the y-axis.
We will assume that b = 0 since it really doesn’t matter where exactly the line intersects the y-axis. We are looking for a delta/change and not specific coordinates. Does that make sense?
So now you have a lovely equation of:
y = (2/3)*x
You know y at 2 points (10 and 4) and now you just need to find the x location for those 2 points (x1 and x2).
10 = (2/3) * x1 and 4 = (2/3) * x2
x1 = 15 x2 = 6
To figure out how far the ball has rolled horizontally along the x, you just find the difference between x1 and x2.
x1 – x2 = 9. So the answer is b.
You don’t need to draw the graph, but it might also be beneficial to draw it out as mrshunnybunches did just to get a visual. However, you don’t want to rely on plotting alone. It works nicely in this problem, but it won’t always.
Post # 12
@RunsWithBears: I totally knew there was a better way to do this!! 😉