4(0.8+X)=7.2
4(0.8+X)/4=7.2/4
0.8+X-0.8=1.8-0.8
X=1
5(X-6.5)=1.7
5(X-6.5)/5=1.7/5
X-6.5+6.5=0.34+6.5
X=6.84
(X-1.8)/4=2.5
(X-1.8)/4×4=2.5×4
X-1.8+1.8=10+1.8
X=11.8
3(4+X)=12.09
3(4+X)/3=12.09/3
4+X-4=4.03-4
X=0.03
4(0.8+X)=7.2
4(0.8+X)/4=7.2/4
0.8+X-0.8=1.8-0.8
X=1
5(X-6.5)=1.7
5(X-6.5)/5=1.7/5
X-6.5+6.5=0.34+6.5
X=6.84
(X-1.8)/4=2.5
(X-1.8)/4×4=2.5×4
X-1.8+1.8=10+1.8
X=11.8
3(4+X)=12.09
3(4+X)/3=12.09/3
4+X-4=4.03-4
X=0.03