For this case we must solve a system of two equations with two unknowns, given by "x" and "y".
We have:
We multiply (2) by -1:
We add (1) and (3):
Clearing x:
We substitute 
in (2)
Thus, the solution of the system is 
Answer:
The solution of the system is
I’ll do an example problem, and I challenge you to do this on your own!
4x+6y=23
7y-8x=5
Solving for y in 4x+6y=23, we can separate the y by subtracting both sides by 4x (addition property of equality), resulting in 6y=23-4x. To make the y separate from everything else, we divide by 6, resulting in (23-4x)/6=y. To solve for x, we can do something similar - subtract 6y from both sides to get 23-6y=4x. Next, divide both sides by 4 to get (23-6y)/4=x.
Since we know that (23-4x)/6=y, we can plug that into 7y-8x=5, resulting in
7*(23-4x)/6-8x=5
= (161-28x)/6-8x
Multiplying both sides by 6, we get 161-28x-48x=30
= 161-76x
Subtracting 161 from both sides, we get -131=-76x. Next, we can divide both sides by -76 to separate the x and get x=131/76. Plugging that into 4x+6y=23, we get 4(131/76)+6y=23. Subtracting 4(131/76) from both sides, we get
6y=23-524/76. Lastly, we can divide both sides by 6 to get y=(23-524/76)/6
Good luck, and feel free to ask any questions!
Answer:
A (1,-2) B(10,1) C(6,2)
Step-by-step explanation:
You add 4 to the x value and subtract 3 from the y value to get the answer.
The answer is y = 35x + 20.
In order to find this, start with two ordered pairs. For the purpose of this problem, we'll use (1, 55) and (2, 90). Now we use the slope formula to find the value next to x in the equation.
m(slope) = (y2 - y1)/(x2-x1)
In this equation (x1, y1) is the first ordered pair and (x2, y2) is the second. Plug in to the equation and solve.
m = (90 - 55)/(2 - 1)
m = 35/1
m = 35
Now that we have the slope, plug that into the equation along with either point to find the intercept (the last number).
y = mx + b
55 = 35(1) + b
55 = 35 + b
20 = b
Now that we have the slope and intercept, we can use each to fill in those blanks.
y = 35x + 20
