If 4x+2y=16 and 6x-2y=4 , find the value of (y-x).
A
8
B
2
C
4
D
6
Verified Correct Answer: B.
Step-by-Step Mathematical Solution
Using elimination method:
4x+2y=16 * 6 --> 24x +12y=96 ... eqn iii
6x-2y=4 * 4 --> 24x - 8y = 16 ... eqn iv
Subtract eqn iv from iii
20y = 80
y = 4
Subst. y for 4 in 4x + 2y = 16
--> 4x + 2(4) = 16
--> 4x = 16 - 8
--> 4x = 8
--> x = 2
: The value of (y-x) is 4 - 2 = 2
Source: WAEC / JAMB / NECO Classroom Archive (Record #61192)