For a science experiment, Claudia observes the effects of temperature on a substance. The original temperature is 9°C, and Claudia increases the temperature by 2°C each hour. Then Claudia graphs the relationship between time and temperature. What is the y-intercept of Claudia’s graph and what does it represent?

The drop in temperature is 42-(-54)=42+54=96℉. Rate of drop is 12℉. So it will take 96/12=8 hours.

Another way: -54-42=-96, -96/-12=8 hours.

Step-by-step explanation:

see explanation

step-by-step explanation:

a

(6r + 7) + (13 + 7r) ( remove brackets and collect like terms )

= 6r + 7 + 13 + 7r

= 13r + 20

b

remove brackets and collect like terms

13 - r - 1 + r

= 12 - r

c

remove brackets and collect like terms

= - 8 - r + 2r - 4

= - 12 + r

d

remove brackets and collect like terms

= 7r - - - 6r

[-   - = - - = - ]

= r -