Answer:
x=13
Step-by-step explanation:
if you will substitute the value of f(x) with 5, you will get the following equation:
5=2x-21
2x=26/÷2
x=13
(I didn't know what you ment when you wrote x2, is it x square or 2X)
I really hope it was the second one, cause that's how I solved it.
7. 324m squared
8. 166mm squared
9. 49.2yd squared
sorry I'm too lazy to do the rest
Answer:
-2x-5y+8z+4.5=0
Step-by-step explanation:
Let (x,y,z) be the coordinates of the point lying on the needed plane. This point is equidistant from the points (-3, 5, -4) and (-5, 0, 4), so

Rates like $ per channel is a slope, "m". The added fee is a constant so it's the intercept "b".
y = mx + b
So for the first problem (9)
(a)
y = total cost in dollars
x = number of premium channels
y = 16x + 44
(b) when x = 3 channels
y = 16(3) + 44
y = 92 $
the second problem (10)
(a) every 4 years the tree grows by 12-9=3 ft
So the unit rate or slope will be 3 ft per 4 yrs, (3/4). You can see this also by solving for slope "m" using the given points (4,9) and (8,12).
x = number of years
y = height of tree in ft
y = (3/4)x + b
use one of the points to find the y-intercept "b".
9 = (3/4)(4) + b
9 = 3 + b
9 - 3 = b
6 = b
y = (3/4)x + 6
(b) when x = 16
y = (3/4)(16) + 6
y = 12 + 6
y = 18 ft
Calculate out how many times the denominator goes into the numerator. To do that, divide 234 by 8 and keep only what is to the left of the decimal point: