방정식 풀이:X=7(X-12)X-0.4X=0.

방정식 풀이:X=7(X-12)X-0.4X=0.

X=7(X-12)
x=7x-84
6x=84
x=84÷6
x=14
X-0.4X=0.54
0.6x=0.54
x=0.54÷0.6
x=0.9