Question

$find \: x \: is \: 5x - 3.2x - 8 = 225$
​

Answer 1

$5x-3.2x-8=225\quad :\quad x=\frac{1165}{9}$

$\mathrm{Add\:similar\:elements:}\:5x-3.2x=1.8x$

$1.8x-8=225$

$\mathrm{Multiply\:both\:sides\:by\:}10$

$1.8x\cdot \:10-8\cdot \:10=225\cdot \:10$

$\mathrm{Refine}$

$18x-80=2250$

$\mathrm{Add\:}80\mathrm{\:to\:both\:sides}$

$18x-80+80=2250+80$

$\mathrm{Simplify}$

$18x=2330$

$\mathrm{Divide\:both\:sides\:by\:}18$

$\frac{18x}{18}=\frac{2330}{18}$

$\mathrm{Simplify}$

$\bf{x=\dfrac{1165}{9}}$

Answer 2

5x-3.2x-8=225\quad :\quad x=\frac{1165}{9}5x−3.2x−8=225:x=

9

1165

\mathrm{Add\:similar\:elements:}\:5x-3.2x=1.8xAddsimilarelements:5x−3.2x=1.8x

1.8x-8=2251.8x−8=225

\mathrm{Multiply\:both\:sides\:by\:}10Multiplybothsidesby10

1.8x\cdot \:10-8\cdot \:10=225\cdot \:101.8x⋅10−8⋅10=225⋅10

\mathrm{Refine}Refine

18x-80=225018x−80=2250

\mathrm{Add\:}80\mathrm{\:to\:both\:sides}Add80tobothsides

18x-80+80=2250+8018x−80+80=2250+80

\mathrm{Simplify}Simplify

18x=233018x=2330

\mathrm{Divide\:both\:sides\:by\:}18Dividebothsidesby18

\frac{18x}{18}=\frac{2330}{18}

18

18x

=

18

2330

\mathrm{Simplify}Simplify

\bf{x=\dfrac{1165}{9}}x=

9

1165