# Evaluating Expressions by Substitution Exercises

### Example 1

Evaluate -3*x* + 4 for *x* = -2.

### Example 2

Evaluate for *x* = 10.

### Example 3

Evaluate 4*x*^{2} for *x* = -1.

### Example 4

Evaluate 5*y* – 3*y*^{2} for *y *= -2.

### Example 5

Evaluate *z*^{3 }– 18 + *z* for *z* = -2.

### Example 6

Evaluate 4*xyz* + *x* + *y* – *z* for *x* = 2, *y* = 3, and *z* = 5.

### Example 7

Evaluate *b*^{2} – 4*ac* for *a* = 1, *b* = 3 and *c* = -2.