Select the best possible first step to solving the system by first eliminating the x variable. 4x 9y = 21 3x − 8y = 1 multiply t
2 answers:
Answer: The correct option is
(A) multiply the first equation by 3, and multiply the second equation by 4.
Step-by-step explanation: The given system of linear equations is:
We are to select the best possible first step to solve the above system by first eliminating x variable.
Since, we need to eliminate x variable first, so will try to make the coefficients of x in both the equations equal. After that, we will subtract one of the equations from the other to eliminate x.
The co-efficient of x in equation (i) is 4,
and
the co-efficient of x in equation (ii) is 3.
So, to make both of them same, we will take the LCM of the coefficients 4 and 3.
We have
LCM(4, 3) = 12.
Now, we will multiply equation (i) by 3 and equation (ii) by 4 to make both the coefficients in equation (i) and (ii) equal to 12.
Thus, we will multiply first equation by 3 and second equation by 4.
Option (A) is CORRECT.
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