Answer:
[tex]x=4[/tex]
Step-by-step explanation:
[tex]3.9x + 1.4 = 17[/tex]
Having a decimal is not very nice to deal with, so we multiply all sides by 10 to get rid of the decimals.
[tex]3.9x*10+1.4*10=17*10[/tex]
[tex]39x+14=170[/tex]
Subtract 14 from both sides:
[tex]39x+14-14=170-14[/tex]
[tex]39x=156[/tex]
Divide both sides by 39:
[tex]\frac{39x}{39}=\frac{156}{39}[/tex]
[tex]x=4[/tex]
