Question

Use substitution to solve the system.

Answer 1

\[\large\rm y=\color{red}{3x-1}\]\[\rm 4x+5\color{reD}{y}=40\]
first question is solved for y
substitute y for first equation in 2nd equation

Answer 2

okay so then... 4x+6y+40

Answer 3

*4x+6y=40*

Answer 4

oh wait okay 4x+5(3x-1)=40

Answer 5

yes that is correct ^^^^
distribute parentheses by 5 and then combine like terms

Answer 6

distributive property \[\rm a(b-c)=a*b-a*c=ab-ac\]

Answer 7

19x=45... is that right

Answer 8

perfect! solve for x

Answer 9

\[\frac{ 45 }{ 19 }\]

Answer 10

=x

Answer 11

that's right you can divide to get the decimal answer
now substitute x for its value into either first or 2nd equation to solve for y
would be easy if u plug in first equation

Answer 12

\[y=(\frac{ 45 }{ 19})-11\]
\[\frac{- 74 }{ 19}\]

Answer 13

hmm first equation is \[\rm y=3x-1 \]
after replacing x with 45/19 it would be \[y= 3(\frac{45}{19})-1\]

Answer 14

so then \[\frac{ 116 }{ 19}\]

Answer 15

looks good.

Answer 16

okay so y= \[\frac{ 116 }{ 19 }\] and x=\[\frac{ 45 }{ 19 }\]