Answer:
<u>(-4,-7)</u>
Step-by-step explanation:
The process of a reflection across the y axis is simply just switching the x value in (x,y) to a negative. So, (4,-7) and then make 4, a -4. So the resulting image is (-4,-7)
Life expectancy of dollar bill = d
life expectancy of coin = c
d = 1/20 c
substitute value in for c (30)
d = 1/20 * 30
d = 30/20
d = 1.5
life expectancy of a dollar bill = 1.5 years