Explanation:
explain what ? what is the question here ?
to find the intersecting point of both lines ?
if that is the case, then please consider that an intersection point is a point, where both equations deliver the same coordinates. it is the same point for both of them.
in other words, the question is for what pair of (x, y) are both equations true (their left and right sides are equal).
we do this by finding a way to express one variable by an expression in the other variable, and then use that identity in one of the equations to solve for the remaining variable. and then we use that in the other equation to solve for the first variable.
line b gives us such an identity right away.
y = (-1/2)x + 6
we can use that in the line a equation :
2x - ((-1/2)x + 6) = 7
2x + (1/2)x - 6 = 7
2x + (1/2)x = 13
(4/2 + 1/2)x = 13
(5/2)x = 13
5x = 26
x = 26/5 = 5.2
y = (-1/2)×5.2 + 6 = -2.6 + 6 = 3.4