Question

How do you solve by substitution y–3x=7 and 21+9x=3y?

Answer 1

hey mate!!! have the answer

y-3x= 7

y= 7+3x....(1)

9x-3y=-21....(2)

now, in (2)

9x-3(7+3x) =-21

9x-21-9x=-21

0x= 0

x= 0

now, in (1)

y= 7+3x

=7+3(0)

= 7+0

= 7

therefore,

x, y= 0,7

hope this helps!!!