Oldest = 2 times Youngest -> O = 2*Y
Middle = Youngest + 5 -> M = Y+5
All of them together is 57 -> O + M + Y = 57
So you have these three equations:
(1) O = 2*Y
(2) M = Y+5
(3) O + M + Y = 57
Now you want to reduce the number of variables. You can change the second equation to be Y = M-5 and then plug in "M-5" wherever there is currently a Y:
(4) O = 2*(M-5) = 2*M - 10
(5) O + M + (M-5) = 57
which becomes O + 2M = 62
Then you plug in the "O" equation (4) into (5) which gives you
(2M-10) + 2M = 62 which reduces to 4M = 72.
So now I know M is 18.
I can now plug that into my other equations:
(4) O = 2*18 - 10 which means O = 26.
Now I plug that into (1) from the top:
26 = 2*Y which becomes 13 = Y
So now I have O, Y, and M
Oldest is 26
Middle is 18
Youngest is 13
Reading the sentence again, you can see that this makes sense.
So an equation of any line is y=mx+b.
We know that the m, or slope, equals 3.
y=3x+b
Now we find the b, or the y-intercept, by substituting the x and y values into their places.
4=3*1+b
4=3+b
b=1
Now that we have the y-intercept, we just substitute the m and b into the equation and receive our final answer:
y=3x+1
Answer:
y = 3x - 6
Step-by-step explanation:
Find the slope of the line:
3 - 6 / 3 - 4 -> -3/-1 so the slope is 3
Now use the point-slope form to find the slope-intercept form:
y - 3 = 3 (x - 3)
y - 3 = 3x - 9 add three to each side...
y = 3x - 6
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Answer:
To stay within budget, she must use 4.4 gigabytes.
Step-by-step explanation:
Giving the following information:
Fixed cost= $57.50 per month
Variable cost= $4 per gigabyte.
She wants to keep her bill at $75.10 per month.
<u>First, we need to establish the total cost formula:</u>
Total cost= 57.5 + 4*x
x= number of gigabytes
<u>Now, we isolate x:</u>
75.1= 57.5 + 4x
17.6/4= x
4.4= x
To stay within budget, she must use 4.4 gigabytes.
