1. 2x + 3y = 6 (for x) Linear equation
2. D = C - s/n (for s) Depreciation
3. A = 1/2 h(B = b)(for b) Area of Trapezoid
ok, i suppose you want us to solve for the indicated variable.
1. 2x + 3y = 6
=> 2x = 6 - 3y .......................subtracted 3y from both sides
=> x = (6 - 3y)/2 ....................divided by 2 on both sides
=> x = 3 - (3/2)y ....................simplified
2. D = C - s/n
=> D - C = -s/n ......................subtracted C from both sides
=> -n(D - C) = s .....................multiplied both sides by -n
=> s = -n(D - C)
3. A = 1/2 h(B - b)
=> 2A = h(B - b) ...................multiplied both sides by 2
=> 2A/h = B - b ....................divided both sides by h
=> 2A/h - B = -b ...................subtracted B from both sides
=> B - 2A/h = b ....................multiplied both sides by -1
=> b = B - 2A/h ....................rewrite