The product of two perpendicular slopes is always -1
So this is ratios
actual height to shadow height=10 to 18=10:18=10/18=5/9
ratio is 5:9
if the shadow height=12 then find actual height
x:12=5:9 since they should be in the same ratio
x/12=5/9
multiply both sides by 12
x=60/9
x=6 and 6/9
x=6 and 2/3
height of person is 6 and 2/3 foot or 6.66ft or 6ft and 8 inches
To solve for a variable, you need to get it (x) by itself.
x² - 14 + 31 = 63 Add 31 to -14
x² + 17 = 63 Subtract 17 from both sides of the equation
x² = 46 Square root both sides
x =

Check your work by plugging in

for x and then

.

² - 14 + 31 = 63 Square

46 - 14 + 31 = 63 Subtract 14 from 46
32 + 31 = 63 Add
63 = 63

² - 14 + 31 = 63 Square

46 - 14 + 31 = 63 Subtract 14 from 46
32 + 31 = 63 Add
63 = 63
So,
x is
and 
.
Answer:
x=5
Step-by-step explanation:
x^2+25-10x = x^2-25
-x^2 -x^2
25-10x = -25
-25 -25
-10x = -50
x=5
lets check
(5-5)^2 = 5^2-25
0^2 = 25-25
0 = 0
The answer is A. y = arccos(x)