Question

3x-5y=4
9x-2y=7 substitution method​

Answer 1

Answer:

3x - 5y = 4

3x = 4 + 5y

x = (4 + 5y)/3

Now lets substitute, x = (4 + 5y)/3 in the second equation

9x - 2y = 7

9{(4 + 5y)/3} - 2y = 7

3(4 + 5y) - 2y = 7

12 + 15y - 2y = 7

13y = 7 - 12 = -5

y = -5/13

Putting y = -5/13 in the first equation

3x - 5y = 4

3x - 5(-5/13) = 4

3x + 25/13 = 4

3x = 4 - 25/13

3x = (52 - 25)/13

3x = 26/13

x = 2/3