Solve the following simultaneous equations: x+ y = 3/2; x – y = 5/2 and use your result to find the value of 2y + x
- -2
- -1
- 1/2
-
1
- 31/2
The correct answer is: 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.