Answer:7.0711
Step-by-step explanation:
First you will have to use the equation length*width*height. The just plug in 4 for the height, then since the length is 4 times longer plug in 4x, and the width would just be x. SO your equation would be 4*4x*x=6400 ft^3. Then foil it out to get 16x^2=6400, then square root 6400 which will give you80, then divide by 16 so x=5 feet^3. That is your width but you length is 4 times that amount. So for length just do 4(5)=20 feet^3
3/k+3=8/k-2
butterfly (multiply 8 and k+3) and (multiply 3 and k-2) and set them = to eachother
8 (k+3)=3 (k-2)
distribute
8k+24=3k-6
-3k both sides
5k+24=-6
-24 both sides
5k=-30
÷5 both sides
k=-6
number 1 is wrong instead of 15 its 25, number 2 is correct.