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.
3^{1}/_{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.