The elimination method is ideal for solving this system of equations. By which number must you multiply the second equation to eliminate the y-variable, and what is the solution for this system?

The question is incomplete, the complete question is:

The elimination method is ideal for solving this system of equations. By which number must you multiply the second equation to eliminate the y-variable, and what is the solution for this system?

x + 3y = 42

2x − y = 14

A: Multiply the second equation by -3. The solution is x = 12, y = 9.

B: Multiply the second equation by -2. The solution is x = 12, y = 10.

C: Multiply the second equation by 2. The solution is x = 15, y = 9

D: Multiply the second equation by 3. The solution is x = 12, y = 10

The correct option is D.

Step-by-step explanation:

The elimination method is a technique wherein we eliminate the coefficient of any one variable.

The given equations are:

x + 3y = 42

2x − y = 14

We multiply the second equation by (3) and the equations formed are:

x + 3y = 42

6x − 3y = 42

The final equation after eliminating the y-term becomes:

7x = 84

x = 12

Putting value of 'x' in any of the original equation, we get:

⇒ 12 + 3y = 42

⇒ 3y = 30

⇒ y = 10

Hence, the correct option is D.

2.2°  

step-by-step explanation:

let θ = the angle of elevation.

tanθ =77/2020

tanθ = 0.038 12

      θ = tan⁻¹0.038 12

      θ = 2.2°