Answer:
look below
Explanation:
Devon's first step is to multiply the second equation by -2. This is justified by the property of equality known as the multiplicative inverse property, which states that if two quantities are equal, then multiplying or dividing both quantities by the same nonzero number will result in two new quantities that are also equal. In other words, if a = b, then ka = kb for any nonzero constant k.
In this case, Devon is multiplying both sides of the second equation by -2, which is a nonzero number, so the resulting equation will still be an equality. This allows Devon to eliminate the y term in the second equation, which will make it easier to solve the system.