Chapter 3: Q3. (page 122)

Solve each system of equations by using either substitution or elimination.
$\begin{array}{l} 3. y = x + 5 \\ x + y = 9 \end{array}$

Short Answer

Expert verified

The solution of the system of equations is $(2, 7)$ .

Step by step solution

Step-1 – Apply the substitution method of solving equations

The algebraic method of substitution involves solving the one of the two equations for one variable in terms of other variable and then substituting the expression so formed for the variable in the second equation.

Step-2 – Substitute the expression

Since, the first equation is already in expressed for y in terms of x so substitute $y = x + 5$ in the equation $x + y = 9$ and solve.

$\begin{array}{l} x + y = 9 \\ x + x + 5 = 9 \\ 2 x = 4 \\ x = 2 \end{array}$

Thus, the value of x is $2$ .

Step-3 – Substitute the value of variable

To find the value of y, substitute $x = 2$ in the equation $x + y = 9$ and then solve as shown.

$\begin{array}{l} x + y = 9 \\ 2 + y = 9 \\ y = 7 \end{array}$

Thus, the value of y is $7$ .

Hence, the solution of the provided system of equations is $(2, 7)$ .

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Solve each system of equations by using either substitution or elimination.
$\begin{array}{l} 3. y = x + 5 \\ x + y = 9 \end{array}$

Short Answer

Step by step solution

Step-1 – Apply the substitution method of solving equations

Step-2 – Substitute the expression

Step-3 – Substitute the value of variable

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Solve each system of equations by using either substitution or elimination.3.y=x+5x+y=9

Short Answer

Step by step solution

Step-1 – Apply the substitution method of solving equations

Step-2 – Substitute the expression

Step-3 – Substitute the value of variable

One App. One Place for Learning.

Most popular questions from this chapter

Recommended explanations on Math Textbooks

Calculus

Pure Maths

Statistics

Mechanics Maths

Probability and Statistics

Geometry

Study anywhere. Anytime. Across all devices.

Solve each system of equations by using either substitution or elimination.
$\begin{array}{l} 3. y = x + 5 \\ x + y = 9 \end{array}$