Answer: infinite answers, jk there is like a lot tho
Step-by-step explanation: The sum of x and y is 79. In other words, x plus y equals 79 and can be written as equation A:
x + y = 79
The difference between x and y is 23. In other words, x minus y equals 23 and can be written as equation B:
x - y = 23
Now solve equation B for x to get the revised equation B:
x - y = 23
x = 23 + y
Then substitute x in equation A from the revised equation B and then solve for y:
x + y = 79
23 + y + y = 79
23 + 2y = 79
2y = 56
y = 28
Now we know y is 28. Which means that we can substitute y for 28 in equation A and solve for x:
x + y = 79
x + 28 = 79
X = 51
Summary: The sum of the two numbers is 79 and their difference is 23. What are the two numbers? Answer: 51 and 28 as proven here:
Sum: 51 + 28 = 79
Difference: 51 - 28 = 23
Please give me brainliest
Answer:
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Step-by-step explanation:
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Sorry i dont know but if you want points you could spam things like this and get points
Average speed = (total distance) / (total time)
Average speed = (192 km) / (8 hours) = 24 km per hour .
OK, so the graph is a parabola, with points x=0,y=0; x=6,y=-9; and x=12,y=0
Because the roots of the equation are 0 and 12, we know the formula is therefore of the form
y = ax(x - 12), for some a
So put in x = 6
-9 = 6a(-6)
9 = 36a
a = 1/4
So the parabola has a curve y = x(x-12) / 4, which can also be written y = 0.25x² - 3x
The gradient of this is dy/dx = 0.5x - 3
The key property of a parabolic dish is that it focuses radio waves travelling parallel to the y axis to a single point. So we should arrive at the same focal point no matter what point we chose to look at. So we can pick any point we like - e.g. the point x = 4, y = -8
Gradient of the parabolic mirror at x = 4 is -1
So the gradient of the normal to the mirror at x = 4 is therefore 1.
Radio waves initially travelling vertically downwards are reflected about the normal - which has a gradient of 1, so they're reflected so that they are travelling horizontally. So they arrive parallel to the y axis, and leave parallel to the x axis.
So the focal point is at y = -8, i.e. 1 metre above the back of the dish.
Based on the two different purchases, you can write equations for the price of a hotdog (h) and that of a drink (d). These equations can be solved by your favorite method to find the individual prices.
... 6h +4d = 17.00 . . . . . . Carl's purchase
... 3h +4d = 12.50 . . . . . . Susan's purchase
We can see that the difference in purchase cost (of $4.50) is due entirely to the difference in the number of hotdogs (3). Thus, the price of a hotdog must be
... $4.50/3 = $1.50
The 4 drinks are then ($12.50 -4.50) = $8, so must be $2 each. You don't need to figure the cost of a drink to determine that the appropriate answer choice is ...
... D. $1.50 for a hot dog; $2.00 for a drink.
