Answer:
The solution is x = -2, y = -3
Step-by-step explanation:
Let's start with the equation 3x + y = -9
Substitute the y for 5x+7 seen in the second equation
Now you have 3x + (5x+7) = -9
Lets solve:
Let's add the x's
Now we have 8x + 7 = -9
Substracy seven from each side
Now we have 8x = -16
Now let's divide 8 on each side
Now we have x = -2
Now lets plug in -2 to the second equation
The second equation is y = 5x+7
When we plug in -2 we get y=5(-2)+7
We multiply
We now have y = -10+7
Add
y = -3
The solution is x = -2, y = -3
Answer: 
Step-by-step explanation:
For this exercise you need to remember:
1) The mulitplication of signs:
2) By definition, like terms contain the same variables with the same exponent.
Then knowing this, and given the equations:
and 
You must subtract the like terms, which means that you must subtract the numerical coefficients of each term.
Then, you get the result is:
Answer:
30.9717685346
Step-by-step explanation:
20/2-10/5. You divide 20 by 2 and subtract that from 10 divided by 5
