解方程;20x+10x(45-x)=650

问题描述:

解方程;20x+10x(45-x)=650

20x+10x(45-x)=650
20x+450x-10x^2=650
10x^2-470x+650=0
x^2-47x+65=0
x1=47/2+1/2*根号1949
x2=47/2-1/2*根号1949

20x+450-10x=650
20x-10x=650-450
10x=200
x=20

20x+10x(45-x)=650
20x+450-10x=650
10x+450=650
10x=650-450
10x=200
x=20

20x + 450 - 10x = 650
20x - 10x = 650 - 450
10x = 200
x = 20