The first step is to combine like terms on both sides of the equation. In this case, we can simplify 10 - 2x to 8x and 90 - x to 89 - x. The equation then becomes 8x = 89 - x.
To isolate the variable x, we need to get rid of any constants on the same side as x. In this case, we can add x to both sides of the equation to get 8x + x = 89. This simplifies to 9x = 89.
After isolating the variable x, we need to divide both sides of the equation by the coefficient of x. In this case, the coefficient is 9, so we divide both sides by 9 to get x = 89/9. This can be simplified to x = 9.89 or 9 8/9.
To check if the solution is correct, we can substitute the value of x back into the original equation. In this case, x = 9.89. So the equation becomes 10 - 2(9.89) = 90 - 9.89. This simplifies to 10 - 19.78 = 80.11. The left side is equal to -9.78 and the right side is equal to 80.11, so the solution is correct.
Yes, this equation can also be solved using the elimination method or the substitution method. However, the method used in this example, which is combining like terms and isolating the variable, is the most efficient and straightforward method for solving this type of equation.