Answer:
Different ways to solve a system of linear equations:
- isolate one variable in one equation and replace it in the other equation
- multiply/divide one equation by a constant and then add/subtract it to the other one, so that only one variable remains
- graph the equation and look at the intersection point
If you graph the system:
- there is only one solution if the lines intersects at only one point
- there is no solution if the lines don't intersect each other (they are parallel)
- there are infinitely many solutions if the lines overlap each other (they are the same equation multiplied by some constant)
Step-by-step explanation:
1st system
y = -x – 7
y = 4/3 x – 7
solution: x= 0, y = 7
2nd system
y = -3x – 5
y = x + 3
solution: x = -2, y = 1
3rd system
y = -2x + 5
y = 1/3 x – 2
solution: x = 3, y = -1
4th system
3x + 2y = 2
x + 2y = -2
solution: x = 2, y = -2
5th system
x + 3y = -9
2x – y = -4
solution: x = -3, y = -2
6th system
x – 2y = 2
-x + 4y = -8
solution: x = -4, y = -3
7th system
5x + y = -2
x + y = 2
solution: x = -1, y = -3
Hey there!
To solve this system of equations, you will need to get one of the terms in both equations to cancel out to zero. If there isn't a term that you can cancel out, you can multiply either or both equations to make that term. There's no wrong way to do this, just as long as you make sure that you double check whether your should add or subtract. This is easier shown than explained, so refer below:
<span> x + y = +1
5x + y = –6
</span>–1(x + y = +1)
5x + y = –6
–x – y = –1
5x + y = –6
You can see that once we combine these equations by adding, the y term will become 0, eliminating it. This is necessary for solving the system, so make sure you do it. Also, remember to distribute the term that you need to to all of the numbers in the equation! After that, just solve for the variable that's still in the equation.
–x – y = –1
+ 5x + y = –6
4x + 0y = –7
4x = –7
x = –1.75
Now, just plug the value we found for x into either one of your equations in the original system as it's presented in your problem.
x + y = 1
–1.75 + y = 1
+1.75 +1.75
y = 2.75
All that's left to do is check your point (–1.75, 2.75). If it's true for both equations, your answer is correct!
–1.75 + 2.75 = 1
<span>5(–1.75) + 2.75 = –6
</span>(–1.75, 2.75) is the solution to your system.
Hope this helped you out! :-)
6 + 3 or you could do 4.5 + 4.5. but the first one is probably what they're looking for.
However because you can use however as “but”