Question

where did i go wrong o_O

For the following system, if you isolated x in the first equation to use the Substitution Method, what expression would you substitute into the second equation?

-x + 2y = -6
3x + y = 8

-2y + 6

2y - 6

2y + 6

-2y - 6

Answer 1

i multipied top equation by 3 to elimanate X then left 7y = -8

Answer 2

well... your elimination is.... close, no there, but close
but you're asked to do it by using substitution

and not to solve it, just to get the expression that will be used in the 2nd
by substituting the expression from the 1st one

Answer 3

ahh so -2y one

Answer 4

but -6 or + 6 so we want to cpmpletely wipe it out? if so add 6

Answer 5

\(\large \begin{array}{llll}
-x + 2y = -6&\implies 2y+6={\color{brown}{ x}}\\
\hline\\
3{\color{brown}{ x}} + y = 8&\implies 3({\color{brown}{ 2y+6}})+y=8
\end{array}\)

Answer 6

\[-x + 2y = -6\]

1) subtract 2y from both sides (to isolate variable x)
2) divide both sides by -1 (to make it x=....)

Answer 7

so would it be a ) -2y + 6

Answer 8

No

Answer 9

im confused then ?

Answer 10

wats r=the answer?

Answer 11

\(\bf -x + 2y = -6\qquad {\color{brown}{ +x}}
\\ \quad \\
\cancel{ {\color{brown}{ +x}}-x } + 2y = -6{\color{brown}{ +x}}\qquad {\color{brown}{ -6}}
\\ \quad \\
{\color{brown}{ -6}}+2y=\cancel{ -{\color{brown}{ -6}}+6 }+x\)

Answer 12

you'd solve for "x" on the 1st equation
and substitute THAT X on the 2nd equation\(\large \begin{array}{llll}
-x + 2y = -6&\implies 2y+6={\color{brown}{ x}}\\
\hline\\
3{\color{brown}{ x}} + y = 8&\implies 3({\color{brown}{ 2y+6}})+y=8
\end{array}\)

Answer 13

im confused here

Answer 14

?

Answer 15

ok....what part?

Answer 16

we add -2 to cancel the ys

Answer 17

but dpnt get wat next

Answer 18

you might be thinking about the "elimination" procedure, but you're asked to use "substitution" instead

Answer 19

are we trying to get rid of x or y ?

Answer 20

can u tell me answe and ill try work it out

Answer 21

\(\bf \text{For the following system,}\\
\text{ if you isolated x in the first equation to use }\\ {\color{red}{ \text{ the Substitution Method }}} , \\
\textit{what expression would you substitute into the second equation?}\)

Answer 22

i thought u could on sub in a solved wquation

Answer 23

well... you could, yes, since they all correlate, it's just that the exercise only requires you to do it in certain way

Answer 24

so a is the right answer?

Answer 25

plz mayun , so tired

Answer 26

hmm

Answer 27

what expression would you substitute into the second equation? <--- meaning, what would you get for "x" from the 1st equation

Answer 28

\(\bf -x + 2y = -6\qquad {\color{brown}{ +x}}
\\ \quad \\
\cancel{ {\color{brown}{ +x}}-x } + 2y = -6{\color{brown}{ +x}}\qquad {\color{brown}{ -6}}
\\ \quad \\
{\color{brown}{ -6}}+2y=\cancel{ -{\color{brown}{ -6}}+6 }+x\)

Answer 29

o_O really have no idea

Answer 30

-6 + 2y = x so we need to add 6 andd - 2?

Answer 31

hmm I have an extra -.... but anyhow \(\bf \bf -x + 2y = -6\qquad \qquad {\color{brown}{ +x}}
\\ \quad \\
\cancel{ {\color{brown}{ +x}}-x } + 2y = -6{\color{brown}{ +x}}\qquad \qquad {\color{brown}{ -6}}
\\ \quad \\
{\color{brown}{ -6}}+2y=\cancel{ {\color{brown}{ -6}}+6 }+x\)

Answer 32

y is y not byitself?

Answer 33

thought we isolate y

Answer 34

X = -6 + 2y

Answer 35

\(\bf \text{For the following system,}\\
\text{ if you isolated } {\huge x} \textit{ in the first equation to use }\\ {\color{red}{ \text{ the Substitution Method }}} , \\
\textit{what expression would you substitute into the second equation?}\)

Answer 36

yeap, x = -6+2y or 2y-6