Помогите плиз Алгебра 7 класс

$(5-7a)^{2} -(5a-3)(4-3a)=$
$=25-70a+49a^{2} -(20a-15a ^{2} -12+9a)=$
$=64a ^{2}-99a+37$

$2(3-2x)(4x-5)-3(x-8)^{2} =$
$=24x-30-16x^2+20x-3x^2-48x-192$
$=-19x^2-4x-222$

$(p+q)^2-(q-r)^2+(r+p)^2=$
$=p^2+2pq+q^2-q^2+2qr-r^2+r^2+2rp+p^2=$
$=2p^2+pq+2qr+2rp$

$2m(3m=4n)^2-5n(3n+4m)^2=$
$=2m(9m^2+24mn+16n^2)-5n(9n^2+24nm+16m^2)=$
$=18m^3+48m^2n+32mn^2-45n^3-120mn^2-80nm^2$
$=18m^3-45n^3-88mn^2-32m^2n$