I we consider her running times as an arithmetic series with common difference:
43.13 - 43.1 = -.03/2 = -.015, Shelly's time in the fourth race will be 43.1 - .015 = 43.085.
Answer:
19/25
Decimal: 0.76
Percent: 76%
Step-by-step explanation:
Answer:
Bag of windflower bulbs costs $8.50
Package of crocus bulbs costs $17.60
Step-by-step explanation:
Let $x be the price of one bag of windflower bulbs and $y be the price of one package of crocus bulbs.
1. Mark sold 2 bags of windflower bulbs for $2x and 5 packages of crocus bulbs for $5y. In total he earned $(2x+5y) that is $105. So,
2x+5y=105
2. Julio sold 9 bags of windflower bulbs for $9x and 5 packages of crocus bulbs for $5y. In total he earned $(9x+5y) that is $164.50. So,
9x+5y=164.50
3. You get the system of two equations:
From the first equation
Substitute it into the second equation:
9x+105-2x=164.50
7x=164.50-105
7x=59.5
x=$8.50
So,
5y=105-2·8.5
5y=105-17
5y=88
y=$17.60
Answer:
x = 8, and y = 12
Step-by-step explanation:
There are 2 variables, so you need 2 equations to form a system of equations in two variables.
The upper left triangle has all angle measures given: 100, 2x + y, 5x + y. We know that the sum of the measures of the angles of a triangle is 180.
First equation:
100 + 2x + y + 5x + y = 180
Simplify:
7x + 2y = 80 (First equation)
Now we see that the upper and lower sides are parallel, so alternate interior angles are congruent. The angles measuring 2x + y and 5x - y are alternate interior angles and are congruent.
Second equation:
2x + y = 5x - y
Simplify:
3x - 2y = 0 (Second equation)
Now we use the first equation and the second equation as a system of simultaneous equations to solve for x and y.
7x + 2y = 80
3x - 2y = 0
Solve the second equation for 2x.
3x = 2y
Now replace 2y in the first equation with 3x.
7x + 3x = 80
10x = 80
x = 8
Replace x with 8 in the second equation.
3(8) - 2x = 0
24 = 2x
x = 12
Answer: x = 8, and y = 12
No, they forgot to switch variable labels after solving for the independent variable...
y=-8x+4
y-4=-8x
(y-4)/-8=x
Now that you have solved for the independent variable x, you switch the variable labels...
y=(x-4)/-8
f^-1(x)=(x-4)/-8 which should really be rewritten as:
f^-1(x)=(4-x)/8 :P
