How do you solve x=2y+7 and x=Y+4 using substitution?

Question

Use substitution to solve the system of equations

Answer 1

x=2y+7  equation 1

 

x=y+4

y=x-4  equation 2

 

substitute the value of y in equation 1

 

x=2(x-4)+7

x=2x-8+7

x=2x-1

x=1

 

substitute the value of x in equation 2

 

y=1-4

y=-3

 

 

Answer 2

Substitute x from first equation into second

 

2y + 7 = y + 4

 

y = 4 - 7 = -3

 

Substitute value of y into first equation

 

x = 2(-3) + 7

 

x = -6 + 7 = 1

 

:)