R/ r+ 15 = 3/8
Cross multiply: top of one side multiplied by bottom of other side:
R x 8 = 3 x r+ 15
Simplify:
8r = 3r + 45
Subtract 3r from both sides:
5r = 45
Divide both sides by 5:
R = 9
Answer:
Answer 10 min
Step-by-step explanation:
Because if it crawls 40 cm per minute but it goes back 10 cm because of wind then you have to do 40-10 = 30 then you do 300 divided by 30 to get the time.
Hope this helped!!!
Answer:
264
Step-by-step explanation:
well you could have just used a calculator!
METHOD 1
f(3) = 20
f(4) = 30
f(5) = 42
f(6) = 56
rate of change
f(4)-f(3)=10
f(5)-f(4)=12
f(6)-f(5)=14
then the average of change is 10+12+14 /3 = 12
METHOD 2 --- faster
rate of change = f(6)-f(3) / 6-3
= (36+18+2)-(9+9+2) / 3
= 36/3 = 12
