Answer: Hours by Tina practiced this month is 3 times the hours she practiced last month such that 15 x 3 =45 hours.
Step-by-step explanation:
Given : Duration of Tina practiced piano last month= 15 hours
Duration of Tina practiced piano this month= 45 hours
We can see 45 is a multiple of 15 such that 
Therefore, Hours by Tina practiced this month is 3 times the hours she practiced last month such that 15 x 3= 45 hours.
Simplemente necesitas restar tres de siete y dejar tu denominador como 4. Tu respuesta es 4/4, que es lo mismo que 1.
1 hundredth+3 tenths= 3 hundredths
The vertex is (2,-1). Thats your answer.