Question

algebra

Answer 1

do you see that y=3x (the first equation) ?

that means every where you see y in the second equation
you can erase it , and put in (3x) instead.
can you do that ?

Answer 2

how can i do that

Answer 3

like this x+3x=-21

Answer 4

@phi

Answer 5

no it is supposed to end up a little different from that there is a 2 in front of the 3x

Answer 6

so you should get x+2(3x)=-21

Answer 7

almost, but you start with
x+2y= -21
don't leave out the 2

Answer 8

x=−3

Answer 9

yes that is it

Answer 10

WHATS THE FINAL ANSWER?

Answer 11

that is the answer to your own question

Answer 12

x=−3

Answer 13

suppa what you get:
x+2(3x)= -21

remember 2y means 2 times y, and 2(3x) means 2*3*x
or 6x
x+6x= -21

now add 1 x plus 6 more x's

Answer 14

whats the final answer

Answer 15

the answer is knowing how to do it.
the next step is
doing
x+6x= -21

on the left side you have 1 x plus 6 more x's. How many x's do you have?

Answer 16

x=−3

Answer 17

yes that is the next step and yes that is the answer

Answer 18

that the answer?

Answer 19

yes

Answer 20

how cna i plug it in

Answer 21

just place -3 where you see x

Answer 22

(x,−3) like this?

Answer 23

@phi

Answer 24

can you try to do this step by step?

you start with
x+2y= -21

you erase the y and put in (3x) instead. Like this:
x+2(3x) = -21

Answer 25

next, you look at 2(3x) and remember that means 2*3*x
you know 2*3 is 6 (two times three is six)
so you can change 2*3*x to 6*x and people write that as 6x

so now you have
x+6x= -21

Answer 26

next you add x+6x
that means you have 1 x and you add 6 more x's
how many x's do you have ?

Answer 27

Slope: 7
Y-Intercept: 0

Answer 28

you should get
x+6x adds up to 7x
so
x+6x=-21
becomes
7x= -21

you then divide both sides by 7 like this:
\[ \frac{7}{7}x = \frac{-21}{7}\]
and you get
1x= -3 or just
x= -3

to find y use
y= 3*x

replace x with -3 and multiply 3*-3
what do you get ?

Answer 29

-9?

Answer 30

yes, so the solution is (-3,-9)

Answer 31

your the best bro