Answer:
It is not valid since there is more than one variable being changed at one.
Step-by-step explanation:
Jackson changed the brand of soil, but he also changes the amount of water, and the amount of sunlight the plants are receiving, so his conclusion that the soil was more effective is not valid.
The answer to your question is 12b^2
Because 3-12 is -9 pal :)
Answer:(9y-7)(9y+7)
Step-by-step explanation:
81y^2-49
=(9y)^2-(7)^2
=(9y-7)(9y+7)
Answer:
45 minutes have passed
Step-by-step explanation:
1 degree = 1 minute