Which statement best explains why we substitute numbers only for variables and not for coefficients or constants in an algebraic expression?

According to the order of operations, what is the first operation to perform in the expression 3 + 2 · 4²?

Evaluate the expression (4/5)m - (1/2)n for m = 10 and n = 3.

Which of the following expressions yields the largest numerical value when evaluated at t = −3? Compare the four choices by evaluating each expression for A, B, C, and D.

A: −2t²

B: (−2t)²

C: −2t³

D: 2(−t)²

A projectile's height is modeled by h(t) = -16t² + vt + s. If v = 64 ft/s and s = 5 ft, compute the height h(2). Use the appropriate mathematical methods.