Question

What is the substitution 3x-5y=11;x=3y+1

Answer 1

3x-5y=11 ------- 1

x=3y+1――――2

from 2 make x subject of the formula

x=3y+1――――3

so put （3y+1）for x in 1

3（3y+1）-5y=11

9y+3-5y=11

4y+3=11

4y=11-3

4y=8

divide both side by 4

y=2――――4

put 2 for y in 3

x=3y+1

x=3（2）+1

x =7

Answer 2

Substitute 3x+1 for x. Then solve from there