Let's set up some simultaneous equations. Let the number of nickels be n, and the number of quarters be q. Now I'm from England so I had to look up the value of a nickel (I could guess the quarter though to be 25c), but apparently it's 5c
Okay we know that the total value of the coins is 150. This gives:
25q + 5n = 150
Rearranging to make n the subject:
n = 30 - 5q
Next, we use the second statement:
n = 2q - 5
Substituting this into the first equation:
2q - 5 = 30 - 5q
7q = 35
q = 5
Putting this value for q into the first equation:
n = 30 - 5(5) = 5
Hence he has 5 of each coin. I hope this helps :)
Answer:
Step-by-step explanation:
See the figure below.
This is how you graph directly from the equation in the slope-intercept form (y = mx + b) without having to create a table of x and y values.
The equation is
y = -2/3 x + 1
Compare it with
y = mx + b
b = 1
The y-intercept is 1, so mark 1 on the y-axis. (You already did.)
I placed a black dot there.
The slope is m.
m = -2/3
slope = m = rise/run
A slope of -2/3 can be though of as -2 rise and 3 run. That means start from the y-intercept, and go -2 in y (a rise of 2 down) and 3 in x (a run 3 right). Point graphed in red.
Mathematically, -2/3 is the same as 2/(-3), so starting again from the y-intercept, this slope can also be though of as rise of 2 in y (a rise of 2 up) and a run of -3 in x (a run of 3 left). Point graphed in green.
The line is graphed in blue.
You can break down 104 into 100 and 4 and break down 57 into 50 and 7:
100*50
+
100*7
+
4*50
+
7*4
Ok, so basically, proportionate pieces mean that the lengths in each section of the diagram are proportional:
2/q = 3/4 = 4/p
Using this, you could find that q = 2/3 and p = 4/3