Question

find the sum 2/5+3/8​

Answer 1

Step-by-step explanation:

I hope this will help you

Answer 2

Answer:

$\dfrac{2}{5}+\dfrac{3}{8}=\dfrac{31}{40}\quad \left(\mathrm{Decimal:\quad }\:0.775\right)$

Step-by-step explanation:

$\dfrac{2}{5}+\dfrac{3}{8}$

$\mathrm{Least\:Common\:Multiplier\:of\:}5,\:8$

$\mathrm{Prime\:factorization\:of\:}5:\quad 5$

$\mathrm{Prime\:factorization\:of\:}8:\quad 2\cdot \:2\cdot \:2$

$\mathrm{Multiply\:each\:factor\:the\:greatest\:number\:of\:times\:it\:occurs\:in\:either\:}5\mathrm{\:or\:}8$

$=5\cdot \:2\cdot \:2\cdot \:2$

$\mathrm{Multiply\:the\:numbers:}\:5\cdot \:2\cdot \:2\cdot \:2=40$

$=40$

$\mathrm{Adjust\:Fractions\:based\:on\:the\:LCM}$

$\mathrm{Multiply\:each\:numerator\:by\:the\:same\:amount\:needed\:to\:multiply\:its}$ $\mathrm{corresponding\:denominator\:to\:turn\:it\:into\:the\:LCM}\:40$

$\mathrm{For}\:\dfrac{2}{5}:\:\mathrm{multiply\:the\:denominator\:and\:numerator\:by\:}\:8$

$\dfrac{2}{5}=\dfrac{2\cdot \:8}{5\cdot \:8}=\dfrac{16}{40}$

$\mathrm{For}\:\dfrac{3}{8}:\:\mathrm{multiply\:the\:denominator\:and\:numerator\:by\:}\:5$

$\dfrac{3}{8}=\dfrac{3\cdot \:5}{8\cdot \:5}=\dfrac{15}{40}$

$=\dfrac{16}{40}+\dfrac{15}{40}$

$\mathrm{Since\:the\:denominators\:are\:equal,\:combine\:the\:fractions}:\quad \dfrac{a}{c}\pm \dfrac{b}{c}=\dfrac{a\pm \:b}{c}$

$=\dfrac{16+15}{40}$

$\mathrm{Add\:the\:numbers:}\:16+15=31$

$=\dfrac{31}{40}$