Answer: 17) 150°C 18) 17 minutes
Step-by-step explanation:
x represents time in minutes and y represents temperature in Celsius
17) y=10x+30
y=10(12)+30
y=120+30
y=150 - Therefore, the water temperature will be 150°C after 12 minutes
18) 200=10x+30
10x+30=200
10x+30-30=200-30
10x=170
x=17 - Therefore, the water temperature will reach 200°C after 17 minutes
