Question

X+y = 8 and 2x-y=7
Anyone can help​

Answer 1

Hello

Explanation:

Méthode par combinaisons linéaires:

`\left\{ \begin{array}cccx+y&=&8&1&-2\\2x-y&=&7&1&1\\\end {array} \right.\\\\\\\left\{ \begin{array}{ccc}3x&=&15\\-3y&=&-9\\\end {array} \right.\\\\\\\boxed{\left\{ \begin{array}{ccc}x&=&5\\y&=&3\\\end {array} \right. }\\`

Proof:

5+3=8 and 2*5-3=7

Answer 2

Explanation:

x=8-y

2x-y=7

2(8-y)-y=7

16-2y-y=7

-3y=-9

y=3

x=8-y

x=8-3=5