Question

Can someone teach me systems of equations?

Answer 1

a linear system is simply a set of linear equations.

Answer 2

Ok, but can you give me an example so i can try?

Answer 3

here's an easy one:

2x + y = 3
x + y = 1

Answer 4

2x + y = 3
+ x + y = 1
Is this the right first step?

Answer 5

you can do 3 different things to solve a linear system:

1. graph the equations, and find where they intersect.
2. substitution
3. elimination.

Answer 6

Im gonna do elimination then substitution

Answer 7

No wait

Answer 8

I cant do elimination on this one

Answer 9

2x + y = 3
+ x + -y = 1-2y

3x=4-2y

Answer 10

That cant be right

Answer 11

you can; in fact elimination would be the easy way out of this one

Answer 12

WAIT

Answer 13

Can i divide the equations?

Answer 14

if you subtract equation 2 from equation 1: you get

x = 2
x + y = 1

next step is to subtract the new equation 1 from equation 2

Answer 15

y=1?

Answer 16

you can't really divide the equations

Answer 17

Ok, i see why now

Answer 18

Give me another one so i can try, i think i see the pattern

Answer 19

2x + y = 5
x + y = 3

Answer 20

2x + y = 5 - x + y = 3 = x=2? The y's cancel out right?

Answer 21

Now i can substitute to get y

Answer 22

right

Answer 23

2 + y = 3
y=1

Answer 24

I can cross check this with the other equation

Answer 25

4 + 1 = 5
2 + 1 = 3