Factorise the expression and divided them as directed:

$(5p^2-25p+20)÷(p-1)$

Factorise the expression and divide them as directed: $4yz(z^2+6z-16)÷2y(z+8)$

Evaluate: $5pq(p^2-q^2)÷2p(p+q)$

Find: $12xy\left(9x^2-16y^2\right)÷4xy\left(3x+4y\right)$

Find: $39y^3\left(50y^2-98\right)÷26y^2\left(5y+27\right)$

Find and correct the errors in the following mathematical expression:

$4\left(x-5\right)=4x-5$

Find and correct the errors in the mathematical statement: $4(x-5)=4x-5$

Find and correct the errors in the mathematical statement: $x(3x+2)=3x^2+2$

Find and correct the errors in the mathematical statement: $2x+3y=5xy$