Answer:
Step-by-step explanation:
In this case, the example is missing the negative sign.
This is an example of scientific notation, which is used to reduce a very large number into a short expression like: 0.000000005, which is reduced in the expression .
It's important to say that the negative sing in the exponent, indicates that all zeros that are being reduce, are placed at the right of the number. Also, to apply a correctly scientific notation, the number reduced should be between 0 and 10.
Answer:
Martin family: 20 hours
Lewis family: 35 hours
Step-by-step explanation:
Let's say that the Lewis family sprinklers were out for L hours and the Martin family's sprinklers were out for M hours. We know that for each hour that the Lewis family sprinkler was on, 30L of water was put out. We can thus write the Lewis family sprinkler water output as 30L per each hour of L = 30 * L. Similarly, the Martin family sprinkler water output = 15 * M .
We know that the total hours for the sprinklers is 55, so L + M = 55. The total water output for the sprinklers is the sum of the sprinkler outputs, so 30 * L + 15 * M = 1350
L + M = 55
30 * L + 15 * M = 1350
One way to solve this would be to solve for L in the first equation and substitute that into the second
subtract M from both sides in the second equation
55 - M = L
30 * (55-M) + 15 * M = 1350
30 * 55 - 30 * M + 15 * M = 1350
1650 - 15M = 1350
subtract 1650 from both sides to isolate the M and its coefficient
-15M = -300
divide both sides by -15 to isolate M
M = 20
L = 55-20 = 35
First, we will find the value of k
We can do this by sybstituting y=24, x=6 in;
y=kx and then solve for k
24= k(6)
divide both-side of the equation by 6
24/6 = k
4 = k
k=4
Then when x = 5, we will substitute x=5 and k=4 in; y=kx and then solve for y
y= (4)(5)
y = 20
Answer:
$30
Step-by-step explanation:
because
So you need to come up with a perfect square that works for the x coefficients.
like.. (2x + 2)^2
(2x+2)(2x+2) = 4x^2 + 8x + 4
Compare this to the equation given. Our perfect square has +4 instead of +23. The difference is: 23 - 4 = 19
I'm going to assume the given equation equals zero..
So, If we add subtract 19 from both sides of the equation we get the perfect square.
4x^2 + 8x + 23 - 19 = 0 - 19
4x^2 + 8x + 4 = - 19
complete the square and move 19 over..
(2x+2)^2 + 19 = 0
factor the 2 out becomes 2^2 = 4
ANSWER: 4(x+1)^2 + 19 = 0
for a short cut, the standard equation
ax^2 + bx + c = 0 becomes a(x - h)^2 + k = 0
Where "a, b, c" are the same and ..
h = -b/(2a)
k = c - b^2/(4a)
Vertex = (h, k)
this will be a minimum point when "a" is positive upward facing parabola and a maximum point when "a" is negative downward facing parabola.
