Total distance John drove=450 miles
total time=8 hours
let the number of hours he drove on highway be x, number of hours he drove on turnpike will be (8-x) hours
since
distance=speed*time
distance traveled in highway=50x
distance traveled in turnpike=60(8-x)
thus the total distance will be:
50x+60(8-x)=450
simplifying the above
50x+480-60x=450
-10x=450-480
-10x=-30
thus
x=3 hours
Thus he drove on highway for 3 hours.
Answer:
C
Step-by-step explanation:
According to SohCahToa, cosine is adjacent over the hypotenuse.
The adjacent when looking from angle b, is 21.
The hypotenuse of this triangle is 29.
So Cos B=21/29
4) You know slope-intercept form is y=mx+b. So using these two given points, you can find the slope!
(-8,5) (-3,10) [Use the y1-y2 over x1-x2 formula to solve for slope]
10 - 5 5
--------- = ----- = 1
-3-(-8) 5
Hurray! You got a slope of one. Now substitute this back into your original equation:
y=mx+b --> y=1x+b
Next, we find what our "b" is, or what our y-intercept is:
Using one of the previous points given, substitute them into the new equation:
[I used the point (-3, 10) ]
y=1x+b
10=1(-3)+b SUBSTITUTE
10=-3+b MULTIPLY
10=-3+b
+3 +3 ADD
----------
13=b SIMPLIFY
So, now we have our y-intercept. Use this and plug it into the equation:
y=1x+b --> y=1x+13
y=1x+13 is our final answer.
5) So for perpendicular lines, your slope will be the opposite reciprocal of the original slope. (Ex: Slope is 2, but perpendicular slope is -1/2)
We have the equation y= 3x-1, so find the reciprocal slope!
--> y=-1/3x-1
Good! Now we take our given point, (9, -4) and plug it into the new equation:
y=-1/3x-1
-4=-1/3(9)+b SUBSTITUTE and revert "-1" to "b", for we are trying to find the y- -4=-3+b intercept of our perpendicular equation.
+3 +3 ADD
--------
-1=b SIMPLIFY
So, our final answer is y=-1/3x+(-1)
6) I don't know, sorry! :(
Answer:
-2
Step-by-step explanation:
given 2 points on a line (x1, yx) and (x2,y2)
the formula for slope, m = (y2-y1) / (x2-x1)
in this case,
x1 = 4, y1 = 3, x2 = 2, y2 = 7
Hence,
m = (7-3) / (2-4) = 4 / -2 = -2
