Объяснение:

1) 4b(7–8a)+a(8a–7)–(14–16a)+(7–8a)ab=4b(7–8a)–a(7–8a)–2(7–8a)+ab(7–8a)=(7–8a)(4b–a–2+ab)

2) –3x(4–5у)–у(4–5у)–3(4–5у)–3ху(4–5у)=(4–5у)(–3х–у–3–3ху)

3) mn(m–3n)–m(m–3n)–n(m–3n)+8(6n–2m)=mn(m–3n)–m(m–3n)–n(m–3n)–16(m–3n)=(m–3n)(mn–m–n–16)