Question

Solve the system of equations by substitution.
X + y = 21
y = 6x

Answer 1

x = 3

y = 18

Explanation:

you replace y with 6x

x + 6x = 21

combine like terms

7x = 21

divide both sides by seven

x = 3

then you plyg 3 into the other equation

y = 6(3)

y= 18

Answer 2

x=3

y=18

Explanation:

x+y=21..........equation 1

or,x=21-y......equation 2

y=6x.......equation3

substituting the value of x in equation 3

y=6(21-y)

or,y=126-6y

or,7y=126

y=18

again,substituting the value of y in equation 2

x=21-y

or,x=21-18

x=3

x=3,y=18