Can somebody me answer question 16 and correct me if i am wrong on question 15 because i am very lost and confused

Ok, So for number 16

Cost/ C= 600

600= 80+ 13n Now subtract 80 from both sides 600-80= 520

520= 13n now just divide both sides by 13 520/13= 40

So the number of people in this group is 40

Now for number 15 Look at the attachment below, I prefer to show my work nicely :-)

book derives an equation for the volume of a pyramid, as shown in figure 2, and numbers mostly in two settings: for the solutions of polynomial equations, and for 9, we would have to solve the equation for y by subtract- 2. the point (1,. 2) is the center of the circle whose equation is x2 y2. 2x. 4y p.w.c. davies.

step-by-step explanation:

x =±sqrt(1/3)

step-by-step explanation:

x+4/6x=1/x

multiply each side by 6x to get rid of the fractions

6x*(x+4/6x)=1/x*6x

distribute

6x^2 +4 = 6

subtract 4 from each side

6x^2 +4-4 = 6-4

6x^2 =2

divide by 6

6x^2/6 = 2/6

x^2 = 1/3

take the square root of each side

sqrt(x^2) = ±sqrt(1/3)

x =±sqrt(1/3)