Question

You need to solve a system of equations. You decide to use the elimination method. Which of these is not allowed?

equation one: 2x - 3y = 12
equation two: -x + 2y = 13

A. Multiply equation 1 by 2 and equation two by 3. Then add the new equations.

B. Multiply the left side of equation 2 by 2. Then subtract the result from equation 1.

C. Multiply equation 2 by -2. Then add the result to equation 1.

Answer 1

B

Explanation:

Answer 2

B

Explanation:

The Elimination Method is the method for solving a pair of linear equations which reduces one equation to one that has only a single variable.

• If the coefficients of one variable are opposites, you add the equations to eliminate a variable, and then solve.
• If the coefficients are not opposites, then we multiply one or both equations by a number to create opposite coefficients, and then add the equations to eliminate a variable and solve.

When multoplying the equation by a coefficient, we multiply both sides of the equation (multiplying both sides of the equation by some nonzero number does not change the solution).

So, option B is not allowed (it is not allowed to multiply only one part of equation)