Consider the system of equations below. y = 3x - 4 x + y = 8 What is the value of x? — SAT

Consider the system of equations below.

y = 3x - 4

x + y = 8

What is the value of $x$ ?

The value of

x

3

To solve the system, substitute the value of

y

from the first equation into the second equation:

x + (3x - 4) = 8

. Combining the

x

terms gives

4x - 4 = 8

. Adding

4

to both sides of the equation results in

4x = 12

. Dividing both sides by

4

isolates the variable, giving

x = 3

Substitute the expression for

y

from the first equation into the second equation.

x + (3x - 4) = 8

This eliminates the variable

y

to create a single equation in terms of

x

Combine the like terms on the left side of the equation.

4x - 4 = 8

Grouping the

x

variables simplifies the expression.

Add

4

to both sides of the equation to isolate the term with

x

4x = 12

Performing the inverse operation of subtraction isolates the variable term.

Divide both sides of the equation by

4

to solve for

x

x = 3

Performing the inverse operation of multiplication isolates the variable

x

Solving a system of linear equations using the substitution method.

Question