Can you help me factor each quadraric expression
x^2+4x-21

Anyone know? will mark brainliest if correct

Follow these steps using the algebra tiles to solve the equation −5x + (−2) = −2x + 4. 1. add 5 positive x-tiles to both sides and create zero pairs. 2. add 4 negative unit tiles to both sides and create zero pairs. 3. divide the unit tiles evenly among the x-tiles. x =

What is an alternate exterior angle