Question

Answer 1

a: \(x\left(2x+1\right)\)

\(=x\cdot2x+x\cdot1\)

\(=2x^2+x\)

b: \(2x\left(x-3\right)\)

\(=2x\cdot x-2x\cdot3\)

\(=2x^2-6x\)

c: \(5x\left(3x^2-4x+5\right)\)

\(=5x\cdot3x^2-5x\cdot4x+5x\cdot5\)

\(=15x^3-20x^2+25x\)

d: \(3x^2\cdot\left(x^2+2x-1\right)\)

\(=3x^2\cdot x^2+3x^2\cdot2x-3x^2\cdot1\)

\(=3x^4+6x^3-3x^2\)