Question

Help for MEDAL

Answer 1

Solve system on equations:

{2x - 3y = 19
{ x + y = 2

Answer 2

multiply the second equation by 2 to get

2x + 2y = 4

then subtract the two equations

Answer 3

2x - 2x = ?

Answer 4

I think it's the y = Mx + b thing and you plug them back in, I am just stuck

Answer 5

you don't have to use y = mx + b

Answer 6

But in school that's what we have to use, and to show our work ;-;

Answer 7

oh, are you talking about substitution?

Answer 8

we can do that too

Answer 9

the second equation is

x + y = 2

we can subtract x from both sides to get

y = -x + 2

with me so far?

Answer 10

Map it out my finals are soon and this is gonna be in it'll at some point.

Answer 11

Yeah I accidentally did the top problem

Answer 12

Then we subtract 2 from both sides right?

Answer 13

not quite

Answer 14

we wanted to get y on one side, and substitute that into the first equation

Answer 15

y = - x + 2

means that we can replace "y" with "-x + 2" whenever y shows up

Answer 16

so

2x - 3y = 19

becomes

2x - 3(-x+2) = 19

solve for x

Answer 17

Oh ok

Answer 18

So we multiply into the parenthesis

Answer 19

2x + 3x - 6 = 19

Answer 20

5x - 6 = 19 whaaaa?

Answer 21

add 6 to both sides

Answer 22

5x = 25

Answer 23

Divide by 5

Answer 24

good, now divide both sides by 5

Answer 25

Answer is 5

Answer 26

Now we plug in for y? or were done

Answer 27

plug in for y

Answer 28

x + y = 2

x = 5

y = ?

Answer 29

5 , -3

Answer 30

Also I don't get this other problem

Answer 31

x^2 - 7x = 0

Answer 32

Solve

Answer 33

Bump

Answer 34

Solve

Answer 35

factor

Answer 36

x^2 - 7x = 0

x(x-7) = 0

what does x equal? you should get two answers

Answer 37

I am confused.

Answer 38

X = 0 so we plug 0 in for x?

Answer 39

yes, x = 0 but there is one more answer

x - 7 = 0
x = ?

Answer 40

X = 7?

Answer 41

Or -7

Answer 42

Subtract from both sides and you get -7

Answer 43

What would you do with 9(x^2 - 4) = 0? Take the parenthesis problem and make it equal zero so like x^2 - 4 = 0?

Answer 44

Ahem..