Question

срочно!!!! пожалуйста, помогите с алгеброй!!

Answer 1

$1) (5x^{2}+8x-7)-(2x^{2}-2x-12)=5x^{2}+8x-7-2x^{2}+2x+12=$
$=3x^{2}+10x+5$

$2) 2x-3-2x^{2}-5x-18=-2x^2-3x-21$

$3)(6a^2-3a+11)-(-3x-a^{3}+7)=6a^2-3a+11+3a+a^{3}-7=$
$=a^{3}+6a^{2}+4$

$4)(14ab-9a^{2}-3b^{2})-(-3a^{2}+5ab-4b^{2})=$
$=14ab-9a^{2}-3b^{2}+3a^{2}-5ab+4b^{2}=9ab-6a^{2}+b^{2}$

$5) (7xy^{2}-15xy+3x^{2}y)+(30xy-8x^{2}y)=$
$=7xy^{2}-15xy+3x^{2}y+30xy-8x^{2}y=7xy^{2}+15xy-5x^{2}y=$
$=xy(7y+15-5x})$

$6) (frac{3}{5}m^{3}n^{2}-frac{1}{4}mn^{2})-(-frac{5}{8}n^{2}m+frac{7}{10}m^{3}n^{2})=$
$=frac{3}{5}m^{3}n^{2}-frac{1}{4}mn^{2}+frac{5}{8}n^{2}m-frac{7}{10}m^{3}n^{2}=$
$=m^{3}n^{2}(frac{3}{5}-frac{7}{10})+mn^{2}(frac{5}{8}-frac{1}{4})=-frac{1}{10}m^{3}n^{2}+frac{3}{8}mn^{2}$