Inactive Tutor answered 02/11/16
Tutor
New to Wyzant
Hi Mary-
This problem requires us to set up two independent equations to solve for two unknowns. The two unknowns are the square footage of each house, and we have enough information to set up the two independent equations.
Let X = House #1 square footage and Y = House #2 square footage.
From the problem statement:
Equation 1: Y = 2*X - 1000 (the 2nd house, Y, has 1000 sq. ft. less than twice the square footage of the 1st house, X)
Equation 2: X + Y = 4400 (the total square footage of both houses equals 4400)
Now plug the "value" for Y from the first equation into the second equation:
X + 2*X - 1000 = 4400
Now solve this equation to determine the value of X:
3*X - 1000 = 4400 (combine X terms)
3*X = 5400 (add 1000 to both sides)
X = 5400/3 (divide both sides by 3 to result in unit X)
X = 1800 sq. ft.
And from the second equation, Y = 4400 - 1800 = 2600 sq. ft.
Check by plugging both numbers into the first equation: 2600 = 2*1800 - 1000 = 3600 - 1000 ...check