Without an equality sign the given terms can't be classed as an equation but if you mean 5(x +2) -3x = 12 then the value of x works out as 1
Using the discriminant for a quadratic equation the value of k works out as plus or minus 12.
2bc + 8b - 3c - 12 is an expression, not an equation or inequality. It cannot, therefore have "an answer".
Negative 12 minus 3 plus 9 is equal to -6
15x minus 8=minus 180 3x+8=24
Yes: the equation is tautological!
That will depend on the plus or minus value of 12 which has not been given.
X=-3
1/5
x=12
It is an equation and the value of c works out as 8
It is an equation and the value of b is 3
12