当a=4,b=2.5,c=6的时候,计算下列格式的值
3c-(a-b)
=3*6-(4-2.5)
=18-1.5
=16.5
2a+b
=2*4+2.5
=8+2.5
=10.5
ab÷(a+c)
=4*2.5/(4+6)
=10/10
=1
2x+4×3=20
2X+12=20
2X=8
X=4
15x-6x=180
9X=180
X=20
1.8÷x=0.3
0.3X=1.8
X=6
2×(x-0.5)=4.6
2X-1=4.6
2X=5.6
X=2.8
10.8x÷0.54=50
10.8X=27
X=2.5