Mac is 5 feet tall and cast a 4 foot 6 inch shadow. at the same time a nearby tree casts a 20 foot shadow what’s the closest high to the tree

I will convert feet to inches.

4 feet, 6 inches = 54 inches

20 feet = 240 inches

5/x = 54/240

Let x = closest height of tree

54x = 5(240)

54x = 1,200

x = 1200/54

x = 22.2222222222

The tree is about 22 feet tall.

x = ±sqrt(10)

step-by-step explanation:

5 - 2x² = -15

subtract 5 from each side

5-5 - 2x² = -15-5

-2x^2   = -20

divide by -2 on each side

-2x^2   /-2= -20/-2

x^2 =10

take the square root on each side

sqrt(x^2 )=±sqrt(10)

x = ±sqrt(10)

check:

5 - 2x² = -15

+sqrt(10)

5 - 2(sqrt(10))² = -15

5 -2(10) = -15

5 -20 = -15

-15 = -15

-sqrt(10)

5 - 2(-sqrt(10))² = -15

5 -2(10) = -15

5 -20 = -15

-15 = -15