(1) Because this equation is a quadratic equation, a≠0.
(2) The coefficient of the first term of this equation is 0, so a+ 1=0, that is, a=- 1.
Equation: -x? +26=0, so x= root number 26.
2. Simplify the original equation and get: (m+ 1)x? +x+( 1-2m)=0
The coefficient of the quadratic term is the same as the sign of the constant term, therefore,
(There are both negative and positive situations)
1)m+ 1 & gt； 0
1-2m & gt； 0
Calculation:-1
2)m+ 1 & lt； 0
1-2m & lt； 0
No answer
To sum up:-1
3. choose 3a+b.
Substitute a into the original equation and get: a? +ab+a=0，
Because a≠0, both sides of the equation are divided by a, a+b+ 1=0, that is, a+b=- 1.