What should be the first step in adding these equations to eliminate y? 12x-2y=-1 + 4x+6y=-4
2 answers:
Answer:
(A) Multiply the top equation by 3
Step-by-step explanation:
The given equations are:
(1)
and (2)
Now, multiplying equation (1) by 3, we get
Also, adding the above equation with equation (2), we get
⇒
⇒
Thus, on multiplying the top equation by 3, we can eliminate y easily.
Hence, option (a) is correct.
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let's say we'll add "x" cups of pure vinegar, pure vinegar meaning is 100% vinegar.
how much vinegar is there in "x" cups of 100% vinegar? well (100/100) * x, or just "x".
how much vinegar is there in 10 cups of 10% vinegar? well, (10/100) * 10, or just 1.
say after adding the "x" cups to the 10 cups, we end up with "y" cups, of 50% of vinegar.
how much is 50% of y? well, (50/100) * y or 0.5y.
bearing in mind that x+10 = y, both cups amounts added up, and that x+1=0.5y, both vinegar amounts added up, thus