=7l-2(3(5l-m)-2(4l+m))

Solution for =7l-2(3(5l-m)-2(4l+m)) equation:

Simplifying
0 = 7l + -2(3(5l + -1m) + -2(4l + m))
0 = 7l + -2((5l * 3 + -1m * 3) + -2(4l + m))
0 = 7l + -2((15l + -3m) + -2(4l + m))
0 = 7l + -2(15l + -3m + (4l * -2 + m * -2))
0 = 7l + -2(15l + -3m + (-8l + -2m))

Reorder the terms:
0 = 7l + -2(15l + -8l + -3m + -2m)

Combine like terms: 15l + -8l = 7l
0 = 7l + -2(7l + -3m + -2m)

Combine like terms: -3m + -2m = -5m
0 = 7l + -2(7l + -5m)
0 = 7l + (7l * -2 + -5m * -2)
0 = 7l + (-14l + 10m)

Combine like terms: 7l + -14l = -7l
0 = -7l + 10m

Solving
0 = -7l + 10m

Solving for variable 'l'.

Move all terms containing l to the left, all other terms to the right.

Add '7l' to each side of the equation.
0 + 7l = -7l + 7l + 10m
Remove the zero:
7l = -7l + 7l + 10m

Combine like terms: -7l + 7l = 0
7l = 0 + 10m
7l = 10m

Divide each side by '7'.
l = 1.428571429m

Simplifying
l = 1.428571429m