Mathematics

Solve the following simultaneous equations: x+ y = 3/2; x – y = 5/2 and…

Solve the following simultaneous equations: x+ y = 3/2; x – y = 5/2 and use your result to find the value of 2y + x

  • A.
    -2
  • B.
    -1
  • C.1/2
  • D.
    1
  • E.
    31/2
Correct Answer: Option D
Explanation

x + y = (frac{3}{2}) … (i)

x – y = (frac{5}{2}) … (ii)

(i) – (ii):

2y = (frac{-2}{2}) = -1

y = (-frac{1}{2})

x + y = (frac{3}{2})

x – (frac{1}{2}) = (frac{3}{2})

x = (frac{3}{2} + frac{1}{2})

= (frac{4}{2})

x = 2

(therefore) 2y + x = 2((-frac{1}{2})) + 2

= -1 + 2 = 1.