What is the sum of the first ten non-zero multiples of twenty

What is the length of the missing leg in this right triangle? 18 mm 24 mm 26 mm 32 mm

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 =

Solve for x where 0 equation: cot^2x+2cotx+1=0