Answer:
B
Step-by-step explanation:
The <u>Elimination Method</u> 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)
17,19,23 are the prime numbers
7 is the prime factor of 210
