An architect presents a 3 inch wide by 4 inch deep by 3 inch tall model of a new central campus dorm . If the final building foundation is 126 feet wide how deep (in feet) will the building be?

Building depth = 168 ft

Step-by-step explanation:

we must find the relationship (scale) of the model with respect to the building .

wide-m (model) = 3 in

deep-m(model) = 4 in

wide-b (building) = 126 feet

deep-b(building) = x

the measures must be standardized

let's convert feet to inches

12 in      →   1 feet

3   in     →   ?,   then

3 in → 0.25 feet and 4 in → 1/3 feet

now deep-m = x

salary

step-by-step explanation:

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