Question

7x + 2y = 4
y = x + 1
Solve the system of equations.

Answer 1

do you have choices?

Answer 2

(1/3, 4/3)

(2/9, 11/9)

no solution

Answer 3

i think its no solution

Answer 4

your right

Answer 5

yay n.n

Answer 6

RyanTLopez what did you get when using substitution?

Answer 7

it's (2/9). (11/9)

Answer 8

First find x...\[7x +2y = 4\]
\[7x + 2y - 4= 0\]
substitute y for x...
\[7x + 2(x+2) - 4 = 0\]
\[9x-2 = 0\]
\[9x = 2\]
\[x = 2/9\]

Answer 9

then plug x in for x in the y equation and solve for y

Answer 10

then hooray :p

Answer 11

im not sure i understand

Answer 12

well... have you covered solving system of equations yet?

Answer 13

oh wait got it

Answer 14

yes

Answer 15

plugging in x into the y equation you get...
\[y = (2/9) + 1\]
which is...
\[y = 2/9 + 9/9\]
and you get...
\[y = 11/9\]

Answer 16

So you're left with (2/9, 11/9)

Answer 17

(x,y)

Answer 18

The solution to your equation would be: \[x = \frac{ 2 }{ 9 }and~y=\frac{ 11 }{ 9 }\]

Answer 19

\(\bf 7x + 2{\color{brown}{ y}} = 4\\
{\color{brown}{ y}} = x + 1\impliedby hint
\\ \quad \\ \quad \\
7x + 2{\color{brown}{ (x+1)}} = 4\implies 7x+2x+2=4\implies 9x=2
\\ \quad \\
{\color{blue}{ x}}=\cfrac{2}{9}
\\ \quad \\
7{\color{blue}{ x}}+2{\color{brown}{ y}}=4\implies 7\left({\color{blue}{ \frac{2}{9}}}\right)+2{\color{brown}{ y}}=4\implies y=?\)

Answer 20

as you can see, the equivalent "y" from the 2nd equation, get SUBSTITUTED in the 1st equaiton
to get "x"

and then plug that back in either equation, to get "y"
thus called "SUBSTITUTION" method