Question

3) Solve the following pair of linear equations by the elimination method and substitution method:
5x+4y=5, x-2y=8​

Answer 1

Step-by-step explanation:

Let

5x+4y=5---(1)

x-2y=8---(2)

$by \: multipling \: eq(1) \: with \: 1 \: \: and \: eq(2) \: with \: 5 \: we \: get \\ 5 x+ 4y = 5 \\ 5x - 10y = 40 \\ ( - ) \: \: \: \: \: ( + ) \: \: \: \: \:\: \: \:( - ) \: \: \: \: \\ = > 14y = - 35 \\ = > y = \frac{ - 35}{14} \\ by \: substitutig \: value \: in \: eq(2) \: we \: get \\ 5x + 4( \frac{ - 35}{14 } = 5 \\ = > 5x + \frac{ - 140}{14} = 5 \\ = > 5x + 10 = 5 \\ = > 5x = 5 - 10 \\ = > 5x = - 5 \\ = > x = \frac{ - 5}{5} \\ = - 1$

hence your answer is

${\boxed{(x,y)=(-1,{\cfrac {-35}{14}})}}$