求下列方程两根的和与积 1.x²-5x-10=0 2.2x²+7x+1=0 3.3x²-1=2x+5 4.x（x-1）=3x+7

求下列方程两根的和与积 1.x²-5x-10=0 2.2x²+7x+1=0 3.3x²-1=2x+5 4.x（x-1）=3x+7
求下列方程两根的和与积 1.x²-5x-10=0 2.2x²+7x+1=0 3.3x²-1=2x+5 4.x（x-1）=3x+7

求下列方程两根的和与积 1.x²-5x-10=0 2.2x²+7x+1=0 3.3x²-1=2x+5 4.x（x-1）=3x+7
x²-5x-10=0   
x1+x2=5
x1x2=-10
 
 2.2x²+7x+1=0
x1+x2=-7/2
x1x2=1/2
 
3.3x²-1=2x+5
3x²-2x-6=0
x1+x2=2/3
x1x2=-2
 
4.x（x-1）=3x+7
x²-x=3x+7
x²-4x-7=0
x1+x2=4
x1x2=-7