Answer:
a=37/14
Please mark me as brainliest hope it helps
Step-by-step explanation:
[tex]\mathrm{Multiply\:both\:sides\:by\:}10[/tex]
[tex]15\cdot \:10-4.2a\cdot \:10<3.9\cdot \:10[/tex]
[tex]\mathrm{Refine}[/tex]
[tex]150-42a<39[/tex]
[tex]\mathrm{Subtract\:}150\mathrm{\:from\:both\:sides}[/tex]
[tex]\mathrm{Simplify}[/tex]
[tex]-42a<-111[/tex]
[tex]\mathrm{Multiply\:both\:sides\:by\:-1\:\left(reverse\:the\:inequality\right)}[/tex]
[tex]\left(-42a\right)\left(-1\right)>\left(-111\right)\left(-1\right)[/tex]
[tex]\mathrm{Simplify}[/tex]
[tex]42a>111[/tex]
[tex]\mathrm{Divide\:both\:sides\:by\:}42[/tex]
[tex]\frac{42a}{42}>\frac{111}{42}[/tex]
[tex]\mathrm{Simplify}[/tex]
[tex]a>\frac{37}{14}[/tex]
