Chapter 3: Q3. (page 150)

If $3 x - y = - 3$ and $x + 5 y = 15,$ what is the value of $y ?$
(A) -3
(B) 0
(C) 1
(D) 3

Short Answer

Expert verified

The value of $y$ is $(D) 3.$

Step by step solution

– Write the given equations

$\begin{matrix} 3 x - y = - 3 . . . . . . . (1) \\ x + 5 y = 15 . . . . . . . (2) \end{matrix}$

– Apply the basic math operations on equations

Multiplying equation (2) by 3, we get

$3 x + 15 y = 45$

It can be rewritten as follows,

localid="1647954222871" $3 x + 15 y - 45 = 0 . . . . (3)$

– Subtract equation (1) from equation (3)

Subtracting equation (1) from (3), we get

$\begin{matrix} (3 x + 15 y - 45) - (3 x - y + 3) = 0 \\ 3 x + 15 y - 45 - 3 x + y - 3 = 0 \\ 16 y - 48 = 0 \\ 16 y = 48 \\ y = \frac{48}{16} \\ y = 3 \end{matrix}$

Thus, the value of $y$ is 3.

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If $3 x - y = - 3$ and $x + 5 y = 15,$ what is the value of $y ?$
(A) -3
(B) 0
(C) 1
(D) 3

Short Answer

Step by step solution

– Write the given equations

– Apply the basic math operations on equations

– Subtract equation (1) from equation (3)

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If3x−y=−3andx+5y=15,what is the value ofy?(A) -3(B) 0(C) 1(D) 3

Short Answer

Step by step solution

– Write the given equations

– Apply the basic math operations on equations

– Subtract equation (1) from equation (3)

One App. One Place for Learning.

Most popular questions from this chapter

Recommended explanations on Math Textbooks

Geometry

Calculus

Probability and Statistics

Pure Maths

Theoretical and Mathematical Physics

Decision Maths

Study anywhere. Anytime. Across all devices.

If $3 x - y = - 3$ and $x + 5 y = 15,$ what is the value of $y ?$
(A) -3
(B) 0
(C) 1
(D) 3