Question

using substitution method , solve 2x+4y = 16 And 4x+8y= 18

Answer 1

Question

using substitution method ,

solve 2x+4y = 16 And 4x+8y= 18

Answer

$\tt{2x + 4y = 16}$

Dividing each term by 2

$\leadsto \tt{ \cancel2x + \cancel4y = \cancel16}$

$\leadsto \tt{\boxed{x + y = 8}}$

$\tt{4x + 8y = 18}$

Dividing each term by 2

$\leadsto\tt{ \cancel4x + \cancel8y = \cancel18}$

$\leadsto{\tt {\boxed{2x + 4y = 9}}}$

Now

2x + 4y = 9

x + y = 8

x + 3y = 1

[x = 1-3y]

Substituting the value of x, we get

$\tt \: x + y = 8$

$\nrightarrow \tt \: (1 - 3y) + y = 8$

$\nrightarrow \tt \:- 3y + y = 8 - 1$

$\nrightarrow \tt \:- 2y = 7$

$\nrightarrow \tt \:y = \frac{ - 7}{2}$

Also

$\tt \: x = 1 - 3 \times \frac{ - 7}{2}$

$\nrightarrow\tt \: x = 1 + \frac{21}{2}$

$\nrightarrow \tt \: x = \frac{2 \times 1 + 21}{2}$

$\nrightarrow \tt \: x = \frac{2 + 21}{2}$

$\nrightarrow \tt \: x = \frac{ 23}{2}$

Hence,

${ \color{navy}\tt \boxed { x = \frac{ 23}{2}}}$

And,

${ \color{olive}\tt \boxed { x = \frac{ - 7}{2}}}$

Answer 2

above solution is perfect you may go through it