Question 149955
# 26


First convert the mixed number {{{b=4&1/5}}} into the improper fraction {{{b=21/5}}} note: let me know if you need help with fraction conversion.



{{{(2/3) ab}}} Start with the given expression.



{{{(2/3)(7)(21/5)}}} Plug in {{{a=7}}} and {{{b=21/5}}}



{{{(2*7*21)/(3*5)}}} Combine the fractions




{{{(2*7*3*7)/(3*5)}}} Factor {{{21}}} into {{{3*7}}}



{{{(2*7*highlight(3)*7)/(highlight(3)*5)}}} Highlight the common terms.




{{{(2*7*cross(3)*7)/(cross(3)*5)}}} Cancel the common terms.



{{{(2*7*7)/(5)}}} Simplify



{{{(98)/(5)}}} Multiply 2, 7, and 7 to get 98




So {{{(2/3) ab=(98)/(5)}}} when {{{a=7}}} and {{{b=21/5}}}



If you want the approximate answer, then  {{{(2/3) ab=19.6}}}  when {{{a=7}}} and {{{b=21/5}}}





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First convert the mixed number {{{m = 7&2/5}}} into the improper fraction {{{37/5}}}. Also, convert the mixed number {{{n = 3&1/4}}} into the improper fraction {{{n=13/4}}}




{{{4 + mn}}} Start with the given expression.



{{{4 + (37/5)(13/4)}}} Plug in {{{a=37/5}}} and {{{b=13/4}}}



{{{4 + (37*13)/(5*4)}}} Combine the fractions.



{{{4 + (481)/(5*4)}}} Multiply 37 and 13 to get 481



{{{4 + (481)/(20)}}} Multiply 5 and 4 to get 20




{{{4(20/20)+(481)/(20)}}} Multiply 4 by {{{20/20}}}. 



{{{80/20+481/5}}} Combine and multiply the fractions.




{{{561/20}}} Add the fractions.



So {{{4 + mn=561/20}}} when {{{a=37/5}}} and {{{b=13/4}}}




If you want the approximate answer, then  {{{4 + mn=28.05}}}  when {{{a=37/5}}} and {{{b=13/4}}}