Question

Solve the simultaneous equations
x + 6y = 20
x + 3y = 14
x =
Y=

Answer 1

x=8

Y=2

or

(x,y)=(8,2)

Explanation:

x+6y=20

x+3y=14

solve the equation for x

x+6y=20

x=14-3y

substitute the given value of x into the equation

x+6y=20

14-3y+6y=20

14+3y=20

3y=20-14

3y=6

3y/3=6/3

y=2.

substitute the given value of y into the equation

x=14-3y

x=14-3×2

x=14-6

x=8.

the possible solution of the system is the ordered pair (x,y)

(x,y)=(8,2)

or

x=8

Y=2

Proof:

Check if the given ordered pair is the solution of the system of equations

8+6×2=20

8+3×2=14

simply the equalities

20=20

14=14

since all of the equalities are true, the ordered pair is the solution of the system

(x,y)=(8,2)

Answer 2

x = 8, y = 2

Explanation:

Multiply the second equation by -2:

x + 6y = 20

-2x - 6y = -28

Add the equations and simplify:

-x = -8

x = 8

Plug x = 8 back into the first equation and solve for y:

8 + 6y = 20

6y = 12

y = 2