Answer:
Step-by-step explanation:
Let's identify what we are looking for in terms of variables. Sandwiches are s and coffee is c. Casey buys 3 sandwiches, which is represented then by 3s, and 5 cups of coffee, which is represented by 5c. Those all put together on one bill comes to 26. So Casey's equation for his purchases is 3s + 5c = 26. Eric buys 4 sandwiches, 4s, and 2 cups of coffee, 2c, and his total purchase was 23. Eric's equation for his purchases then is 4s + 2c = 23. In order to solve for c, the cost of a cup of coffee, we need to multiply both of those bolded equations by some factor to eliminate the s's. The coefficients on the s terms are 4 and 3. 4 and 3 both go into 12 evenly, so we will multiply the first bolded equation by 4 and the second one by -3 so the s terms cancel out. 4[3s + 5c = 26] means that 12s + 20c = 104. Multiplying the second bolded equation by -3: -3[4s + 2c = 23] means that -12s - 6c = -69. The s terms cancel because 12s - 12s = 0s. We are left with a system of equations that just contain one unknown now, which is c, what we are looking to solve for. 20c = 104 and -6c = -69. Adding those together by the method of elimination (which is what we've been doing all this time), 14c = 35. That means that c = 2.5 and a cup of coffee is $2.50. There you go!
You do copies divided by minutes
360/30=12
the printer produces 12 pages per minute
The equation of the line is given as
A straight line equation is given in the form
where
is the gradient and
is the y-interest.
We need to rearrange
to make
the subject.
⇒ from here we can read the gradient and the y-intercept. The gradient,
and
.
<span>A line that is parallel to
will have the same gradient,
but different y-intercept. One example of equation of a line that is parallel to
is
</span>
Answer:
- <u>f(t) = -7.561(t + 1.15)(t - 2.53)</u>
Explanation:
The<em> hint </em>is that the function f can be written in the form:
- f(t) = c (t - t₁) (t - t₂)
It is a quadratic function, i.e. a parabola.
The maximum point, maximum height, of a parabola is its vertex.
And the x-coordinate of the vertex is at the midpoint between the two x-intercepts.
The time when the rock reaches the road is one x-intercept: t = 2.53 seconds: (2.53, 0).
The other x-intercept is sucht that (x + 2.53) / 2 = 0.69
- (x + 2.53) / 2 = 0.69
- x + 2.53 = 1.38
- x = 1.38 - 2.53
- x = -1.15
Thus, the equation is:
- f(t) = c(t + 1.15) (t - 2.53).
You can find c by doing t = 0, because at t = 0 the height, f(t), is 22 feet:
- f(0) = 22 = c (0 +1.15)(0 - 2.53)
- 22 = c(1.15)(-2.53)
- 22 = c (-2.9095)
- c = - 22/(2.9095)
- c = - 7.561
Then, the function can be written as:
- f(t) = -7.561(t + 1.15) (t - 2.53) ← answer
