Understanding Substitution in Algebra

What is the primary purpose of substitution in algebra?

• To solve equations directly

• To simplify expressions without numbers

• To replace variables with their given values

• To find the derivative of a function

If the expression is evaluated when g equals 5, and the result is 19, what is the expression?

• 5g - 6

• 4g - 1

• 2g + 9

• 3g + 4

When substituting g = 12 into the expression, the result is 40. What is the expression?

• 3g + 4

• 2g + 16

• g + 28

• 4g - 8

In a complex expression with variables d and e, if d = 1 and e = 3, what is the first step in evaluating the expression?

• Ignore the values of d and e

• Multiply d and e

• Substitute d and e with their values

• Add d and e together

In an expression where k appears twice, what should you do when substituting a value for k?

• Substitute the value for k only once

• Substitute the value for k each time it appears

• Ignore the second occurrence of k

• Use a different value for each occurrence of k