Answer:
Multiply the first equation by 15 (Answer D)
Explanation:
Writing these equations symbolically, we have:
(2/3)x + (1/5)y = 6
(1/6)x - 3y = 8
Which number can she multiply the first equation by so that when the two equations are added together, the y term is eliminated? After this multiplication, we should have +3y in the first equation; then 3y - 3y = 0 as desired. The coefficient of the y term in the first equation is (1/5), whereas we want it to be +3.
Multiplying the first equation by 15, we get 10x + 3y = 90.
Then our system is:
10x + 3y = 90
(1/6)x - 3y = 8
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(61/6)x = 98 (the variable y has been temporarily eliminated).