2X-2.8x2.5=8.96
2x=8.96+7=15.96
x=7.98
8X+2X=31.4
10x=31.4
x=3.14
2x(X+1)=6
x^2+x-3=0
x=(-1+√13)/2或(-1-√13)/2
7.8X2.4X=1.08
15.6x=0.9
x=9/156
x=3/32
2X-2.8x2.5=8.96
2x=8.96+7=15.96
x=7.98
8X+2X=31.4
10x=31.4
x=3.14
2x(X+1)=6
x^2+x-3=0
x=(-1+√13)/2或(-1-√13)/2
7.8X2.4X=1.08
15.6x=0.9
x=9/156
x=3/32