<h3>
Answer: -7</h3>
Explanation:
Pick any term. Subtract off the previous one to find the common difference.
- term2 - term1 = 6-13 = -7
- term3 - term2 = -1-6 = -7
- term4 - term3 = -8-(-1) = -8+1 = -7
And so on. You only need to pick one of those to show as your steps to your teacher. However, doing all three subtractions is a good way to get practice in seeing how we have an arithmetic sequence. The common difference must be the same each time.
We subtract 7 from each term to get the next term, i.e. we add -7 to each term to get the next one.
Answer:
Step-by-step explanation:
Plug in 4 for x
2(4) + 5y = 28
8 + 5y = 28 (subtract both sides by 8)
5y = 20 (divide both sides by 5)
y = 4
Equation 1) -x - y - z = -8
Equation 2) -4x + 4y + 5z = 7
Equation 3) 2x + 2z = 4
Solving for three variables is quite similar to solving for two variables. Just like when solving for two variables, you look for like variables & solve them one-by-one. So, let's get started! :)
Multiply ALL of equation 1 by four.
1) 4(-x - y - z = -8)
Simplify.
1) -4x - 4y - 4z = -32
Both equations 1 & 2 have the same three variables (x, y, z), so, we must look at these equations together.
1) -4x - 4y - 4z = -32
2) -4x + 4y + 5z = 7
Add these equations together, and create a fourth equation.
4) -8x - z = -25
Now, notice how both equations 3 & 4 have the same two variables (x, z).
So, we must look at these equations together.
3) 2x + 2z = 4
4) -8x - z = -25
Multiply ALL of equation 4 by 2.
4) 2(-8x - z = -25)
Simplify.
4) -16x - 2z =-50
3) 2x + 2z = 4
Now, add the equations together, so that we can solve for x.
-14x = -42
Divide both sides by -14.
x = 3
Now, plug in 3 for x into our 3rd equation.
3) 2x + 2z = 4
3) 2(3) + 2z = 4
Simplify.
6 + 2z = 4
Subtract 6 from both sides.
2z = 4 - 6
Simplify.
2z = -2
Divide both sides by 2.
z = -1
Now, plug in -1 for z & 3 for x in our 1st equation.
1) -x - y - z = -8
-(3) - y - (-1) = -8
Simplify.
-3 - y + 1 = -8
Simplify.
-2 - y = -8
Add 2 to both sides.
-y = -8 + 2
Simplify.
-y = -6
Divide both sides by -1.
y = 6
SO :
x = 3, y = 6, z = -1
~Hope I helped!~
