Question

if 7x+9y=42and 9x+7y=22find the value of x y​

Answer 1

Step-by-step explanation:

7x + 9y = 42 (1)

9x + 7y = 22 (2)

Add

16x + 16y = 64

x + y = 4

Now

(1)

7x + 9y = 42

7 (x + y) + 2y = 42

28 + 2y = 42

2y = 14

y = 7

x = -3

hope it helps

Answer 2

Answer is below

7x+9Y=42 (1)

9x+7y=22 (2)

Multiplying

9 (7x+9y=42)

63x+81y=378 (3)

7 (9x+7y=22)

63x+49y=154 (4)

sub eq (3)-(4)

63x+81y=378

63x+49y=154

y=7

put the value of y in eq (1)

7x+9×7=42

7x+63=42

7x=42-63

7x=-21

x=-21÷7

x=-3