Answer:
number of hours Alexander family ‘s sprinkler work = 20
number of hours Morgan family ‘s sprinkler work = 30
Step-by-step explanation:
Given in the question,
water output rate for the Alexander family ‘s sprinkler = 40 L
water output rate for the Morgan family ‘s sprinkler = 20 L
Suppose, number of hours Alexander family ‘s sprinkler work = x
Suppose, number of hours Morgan family ‘s sprinkler work = y
Equation1
x + y = 50
Equation 2
40x + 20y = 1400
x = 50 - y
Put this value of x in equation 2
40(50-y) + 20y = 1400
2000 - 40y + 20y = 1400
-20y = 1400 - 2000
-20y = -600
y = 30
Put this value of y in equation 1 to get the value of x
x + 30 = 50
x = 50 - 30
x = 20
Answer:
Step-by-step explanation:
Answer:
Choice C: Lauren is faster than Kevin, slower than Jeremy.
Step-by-step explanation:
Ok, so it directly says that Jeremy is going at y=12x, or 12 miles per hour. To find how fast Kevin is riding, take two points of the table and use the slope formula to get the speed(.
Slope Formula: (y2-y1) / (x2-x1)
So lets take the table plots (2, 22) and (4, 33) to do this.
(y2-y1) / (x2-x1)
(33-22) / (4-2)
(11) / (2)
The speed of Kevin is 5.5 miles by hour.
Then, it asks for how fast Lauren is going, saying she is twice as fast as Kevin. Therefore, simply do:
5.5 * 2 = 11 miles per hour
To get the third biker's speed.
Now, with all of the speeds of the bikers, we can now compare them. Here's a listing of their speeds to make things easier to compare:
Jeremy: 12 mph
Kevin: 5.5 mph
Lauren: 11 mph
From this, we can see that Lauren is the second fastest. She is slower than Jeremy but faster than Kevin. Therefore, the correct answer choice is C.
Answer:
x = -1
, y = -4
Step-by-step explanation by elimination:
Solve the following system:
{8 y - 5 x = -27 | (equation 1)
7 y - 8 x = -20 | (equation 2)
Swap equation 1 with equation 2:
{-(8 x) + 7 y = -20 | (equation 1)
-(5 x) + 8 y = -27 | (equation 2)
Subtract 5/8 × (equation 1) from equation 2:
{-(8 x) + 7 y = -20 | (equation 1)
0 x+(29 y)/8 = (-29)/2 | (equation 2)
Multiply equation 2 by 8/29:
{-(8 x) + 7 y = -20 | (equation 1)
0 x+y = -4 | (equation 2)
Subtract 7 × (equation 2) from equation 1:
{-(8 x)+0 y = 8 | (equation 1)
0 x+y = -4 | (equation 2)
Divide equation 1 by -8:
{x+0 y = -1 | (equation 1)
0 x+y = -4 | (equation 2)
Collect results:
Answer: {x = -1
, y = -4
