Answer:
e
Explanation:
let x be the number of one- bedroom and y the number of two - bedroom apartments , then create 2 equations and solve simultaneously.
x + y = 12 ( subtract y from both sides )
x = 12 - y → (1)
360x + 450y = 4950 → (2)
substitute x = 12 - y into (2)
360(12 - y) + 450y = 4950 ← distribute parenthesis and simplify left side
4320 - 360y + 450y = 4950
4320 + 90y = 4950 ( subtract 4320 from both sides )
90y = 630 ( divide both sides by 90 )
y = 7
there are 7 two- bedroom apartments