<em>Answer</em>
B) y = 3
<em>Step-by-step explanation</em>
Given the system of equations:

Isolating x from equation 1:

Substituting equation 3 into equation 2 and solving for y:

There are 130 centimeters in 1.3 meters
Subtracting a negative integer is the same as adding a positive integer. Adding a positive integer to any number always makes the answer larger than the original number. Therefore, if you subtract one negative integer from another your answer will be always be *greater* than the integer you started with.
C) The +10 is because you already have 10 coins, that will not change. The 6x is because with each passing day, the number of coins increase by 6 (x represents days). The equation then turns into y=6x+10
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