Question 821571
---
just break it down into the different "pieces", that's what piece-wise means:
---
when x <= -1 use the first piece-wise function: f(x) = (x^2 + 2x)
why? 
because the function definition tells you to use the first piece when x <= 1
---
so use (x^2 + 2x) to calculate f(-4) and f(-2/3) and f(-1) because those are all the values of x <= -1 that the problems wants solved.
--- 
for f(0) use the second piece-wise function: f(x) = (x)
why? 
you guessed it, because x=0 and the function definition tells you to use the second piece when -1 < x <= 1
---
for f(25) use the third piece-wise function: f(x) = (1)
why? 
because the function definition tells you to use the third piece when x > 1
---
you can do the math on a calculator
---
Solve and graph linear equations:
https://sooeet.com/math/linear-equation-solver.php
---
Solve quadratic equations, quadratic formula:
https://sooeet.com/math/quadratic-formula-solver.php
---
Solve systems of linear equations up to 6-equations 6-variables:
https://sooeet.com/math/system-of-linear-equations-solver.php