有理数范围内自定义运算“*”,其规则为a*b=(a+b)÷3,则方程3*(x*3)=1的解为?
问题描述:
有理数范围内自定义运算“*”,其规则为a*b=(a+b)÷3,则方程3*(x*3)=1的解为?
答
3*(x*3)=1
3 * [(x + 3)/3 ] =1
[3 + (x + 3)/3 ] / 3 = 1
1 + X/9 + 1/3 = 1
X = -3
答
(x*3)=(x+3)/3 3*[(x+3)/3]=1 即:{3+(x+3)/3}/3=1
两边同乘3:3+(x+3)/3=3 再同乘3:9+x+3=9 x=-3
答
3*(x*3)=1
3 * [(x + 3)/3 ] =1
[3 + (x + 3)/3 ] / 3 = 1
即
1 + X/9 + 1/3 = 1
解得
X = -3
答
x*3=(x+3)/3
3*(x*3)=3*(x+3)/3=[3+(x+3)/3]/3=(x+12)/9
(x+12)/9=1
x+12=9
x=-3