Question

find x and y by reduction method 2x+3y=-5 &3x-5y=21​

Answer 1

answer:

multiply 2x+3y=-5 by 3 and other equation by 2

therefore:

6x+9y=-15

6x+10y=42

- - -

---------------

0 -1y = -27

y=27

put y in equation 2

x=38

hope it helps you!!

Answer 2

$\huge {\underline {\bf {Question}}}$

Find x and y by reduction method 2x+3y=-5 & 3x-5y=21

$\huge {\underline {\bf {Solution}}}$

Given equations :

2x + 3y= -5 ------------- i

3x - 5y = 21 ------------- ii

First , multiply 3 to eq.( i )

$3 (2x + 3y) = 3 × -5$

$\implies {6x + 9y = -15}$

Similarly, multiply 2 to eq. ( ii )

$2 (3x - 5y) = 2 × 21$

$\implies {6x + 10y = 42}$

Now , by reduction method , we get

$6x + 10y - (6x + 9y) = 42 - (-15) \\ \implies {6x + 10y - 6x - 9y = 42 + 15} \\ \implies {y = 57}$

$Now , putting\: y = 57 \:in \:eq.(i) , we \:get$

$2x + 3y= -5 \\ \implies {2x + 3 (57)= -5}\\ \implies$