Answer:
Step-by-step explanation:
Multiply the equations together
(5x+4)(5x^2-7x-2)
25x^3-35x^2-10x+20x^2-28x-8
Add like terms
25x^3-15x^2-38x-8
Answer: $27
Step-by-step explanation: First we would like to know how much it costs per pound of apples. To find that out simply divide 10.80 by 6 to find the price for one pound. 10.80/6 = $1.80 per pound of apples.
Now, we want to find out how much 15 pounds of apples cost. Simply multiply 1.80 x 15 to find the price of 15 pounds of apples. 1.80 x 15 = $27 for 15 pounds of apples.
The mean is calculated by adding up all of the given numbers and dividing by the number of numbers.
Lets, for ease of understanding, say that the first three number were 64...
Mean=(64+64+64)/3=192/3=64
Now, lets solve for the mean where 'x' is the unknown fourth number and 128 is the mean. (since, the answer said that when the fourth number was added the mean, 64, was doubled '64*2=128')
128=(64+64+64+x)/4
128=(192+x)/4
Multiply both sides by 4
512=192+x
subtract 192 from both sides
320=x
The missing number is 320..
Now lets double check our work.
Mean=(64+64+64+320)/4=512/4=128
Answer=320
