Question

Viết các biểu thức sau dưới dạng tích:

a)\(m^2-n^2\) c)-16+\(\left(x-3\right)^2\)

b)\(\left(x^2+x-1\right)^2-\left(x^2+2x+3\right)^2\) d)64+16y+\(y^2\)

Answer 1

a) \(m^2-n^2=\left(m-n\right)\left(m+n\right)\)

b) \(\left(x^2+x-1\right)^2-\left(x^2+2x+3\right)^2\)

\(=\left(x^2+x-1+x^2+2x+3\right)\left(x^2+x-1-x^2-2x-3\right)\)

\(=\left(2x^2+3x+2\right)\left(-4-x\right)\)

c) \(-16+\left(x-3\right)^2=\left(x-3\right)^2-16=\left(x-3-4\right)+\left(x-3+4\right)=\left(x-7\right)\left(x+1\right)\)

d) \(64+16y+y^2\)

\(=8^2+2.8.y+y^2\)

\(=\left(8+y\right)^2\)