Question

Solve the system of equations.
– 5x + 2y = 9
y = 7x

X =
Y =

Answer 1

x−y = 9 , x + y = 6

x + y = 4 , x − y = 2

x + 2 y = 4 , x − y = − 3

try out these examples?

Answer 2

x = 1

y = 7

Explanation:

Your system of equations is

-5x + 2y = 9

y = 7x

The easiest way to solve this is by substitution. This means that you set one of the equations equal to a variable and you plug that variable into the variable of the other equation. The second equation (y = 7x) is already set up this way so we will plug it into the first equation.

-5x + 2(7x) = 9

-5x + 14x = 9

9x = 9

(9x)/9 = (9)/9

x = 1

You have found x. Now, plug this number into the second equation (y = 7x) to find the value of y.

y = 7(1)

y = 7