46,141 views
9 votes
9 votes
X+y = 8 and 2x-y=7
Anyone can help​

User Yammi
by
2.9k points

2 Answers

11 votes
11 votes

Answer:

Hello

Explanation:

Méthode par combinaisons linéaires:


\left\{ \begin{array}cx+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

User Bhaskar Vaddadi
by
3.1k points
23 votes
23 votes

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

X+y = 8 and 2x-y=7 Anyone can help​-example-1
User Michael S Priz
by
3.1k points