Question

Looking for some help please.

Use the method of substitution to solve the system of linear equations.
9x+3y=3/2
y=2x-2
The solution is ? (Type an ordered pairs)

Answer 1

sub.s the expression for y in the 2nd equation into the first equation and solve for x

Answer 2

You there?

Answer 3

Hi, yes here I am.

Answer 4

I am new to algebra so I am looking for help in breaking it down to understand the equation please.

Answer 5

See how there's a y in the top equation? and how the bottom equation is solved for y? Take that expression for y (2x-2) and put it into the top equation where the y is... then use algebra to simplify and solve...

Answer 6

Does that part make sense?

Answer 7

9x+3(2x-2)=3/2?

Answer 8

yep:)

Answer 9

can you help me with the next step?

Answer 10

distribute the 3 to (2x-2)

Answer 11

add three or multiply?

Answer 12

multiply

Answer 13

9x+3(2x-2)=3/2?
9x+6x-6=3/2
am I right so far?

Answer 14

looking good:)

Answer 15

combine terms... the terms with 'x' in them are like terms.... so add them..

Answer 16

9x+3(2x-2)=3/2?
9x+6x-6=3/2
15x-6=3/2

Answer 17

the terms with no 'x' in them are like terms so... combine them, which means that that '-6' is going to have to be moved to the other side of the equation to be combined with the '3/2'

Answer 18

great so far... so moving the -6 what do you need to do to get rid of it on the left side?

Answer 19

i'm forgetting what I need to do to get rid of the l eft side...

Answer 20

add 6 to both sides eh? :)

Answer 21

15x-6+6=3/2+6?

Answer 22

yep:)

Answer 23

almost done

Answer 24

15x=3/2+6 is this right?

Answer 25

yes

Answer 26

should write the 3/2 +6 as a single term, for your own ease...

Answer 27

3/2 + 12/2 = ?

Answer 28

15/2

Answer 29

good. last step: divide both sides by the coefficient on x ie divide both sides by 15...

Answer 30

and what do you get for x ?

Answer 31

1/2?

Answer 32

good:) now go back and use that result to find y...

Answer 33

easiest to use it here: y=2x-2 put in '1/2' for 'x'

Answer 34

got it? any questions?

Answer 35

y=2x(1/2)-2?

Answer 36

this seems easy but i get frustrated and lost LOL i think i am making it harder than it is.

Answer 37

uhm use * to signify multiplication or you're going to get it confused with 'x' at some point...

Answer 38

yeah it gets pretty easy eventually:) bit of practice is all...

Answer 39

all good?

Answer 40

y=2*(1/2)-2?

Answer 41

did I set that up right?

Answer 42

yep

Answer 43

simplify

Answer 44

y=2*(1/2)-2?
y=1-2

Answer 45

yes one more little step...

Answer 46

y=1

Answer 47

-1

Answer 48

negative. ok.

Answer 49

:)

Answer 50

so how would "I get the ordered pair. one is -1

Answer 51

"ordered pair" means you write your answer as 'open parenthesis' 'x value' 'comma' y value' 'close parenthesis'

(x,y)

Answer 52

(1/2,-1)

Answer 53

put the results we just got in for 'x' and 'y' though

Answer 54

yep good

Answer 55

wow, i can't believe I got it. LOL NEVER would have without you. thank you!

Answer 56

Sure!