Question 117288
1.

{{{(28(x ^ 5) (y ^ 3)) /(-21x ^ 3 (y ^ 4))}}}….divide {{{28}}} and {{{-21}}} by {{{7}}}

{{{(4x ^ 5 (y ^ 3)) /(-3x ^ 3 (y ^ 4))}}}

{{{(4/-3)x ^ (5-3)* y ^ (3- 4)}}}

{{{-(4/3)*x ^ 2 *y ^ -1}}}

{{{-(4/3)(x ^ 2 /y) }}}

2.

{{{(7x-21) /( x ^2 + x-12)}}}……..factor out common {{{7}}} in nominator, and replace {{{x}}} with {{{-3x+4x}}} in denominator

{{{7(x-3) /( x ^2 -3x+ 4x-12)}}}…. in denominator group first two terms and second two terms together

{{{7(x-3) /( (x ^2 -3x)+ (4x-12))}}}….factor out common {{{x}}} from first two terms, and {{{4}}} from second two terms

{{{7(x-3) /( x(x  -3)+ 4(x-3))}}}….combine like terms

{{{7(x-3) /( x+ 4)(x-3)}}}……..simplify

{{{7 /( x+ 4)}}}……..