Compare Expressions: Finding Equivalence in (6b+3)(a-2) and Related Forms

Question

Which of the following expressions have the same value?

  1. (6b+3)(2+a) (6b+3)(-2+a)

  2. (2b+1)(3a6) (2b+1)(3a-6)

  3. (a+3)(6b2) (a+3)(6b-2)

  4. 6ab+3a12b6 6ab+3a-12b-6

Video Solution

Step-by-Step Solution

To solve this problem, we need to systematically expand and simplify each expression given in the problem statement:

  • Expression 1: (6b+3)(2+a) (6b+3)(-2+a)

    Expand using the distributive property:

    =6b(2)+6b(a)+3(2)+3(a) = 6b(-2) + 6b(a) + 3(-2) + 3(a)

    =12b+6ab6+3a = -12b + 6ab - 6 + 3a

    Reorder terms: 6ab+3a12b6 6ab + 3a - 12b - 6

  • Expression 2: (2b+1)(3a6) (2b+1)(3a-6)

    Expand using the distributive property:

    =2b(3a)+2b(6)+1(3a)+1(6) = 2b(3a) + 2b(-6) + 1(3a) + 1(-6)

    =6ab12b+3a6 = 6ab - 12b + 3a - 6

    This simplifies directly to 6ab+3a12b6 6ab + 3a - 12b - 6

  • Expression 3: (a+3)(6b2) (a+3)(6b-2)

    Expand using the distributive property:

    =a(6b)+a(2)+3(6b)+3(2) = a(6b) + a(-2) + 3(6b) + 3(-2)

    =6ab2a+18b6 = 6ab - 2a + 18b - 6

    This results in 6ab2a+18b6 6ab - 2a + 18b - 6 , clearly different from the others

  • Expression 4: 6ab+3a12b6 6ab+3a-12b-6

    This is already simplified and the same as the results of expressions 1 and 2.

Upon comparing the simplified expressions, expressions 1, 2, and 4 have the same value: 6ab+3a12b6 6ab + 3a - 12b - 6 . Expression 3 differs with 6ab2a+18b6 6ab - 2a + 18b - 6 .

Thus, the expressions with the same value are 1, 2, and 4.

Therefore, the correct answer is choice 4: 1,2,4 1,2,4 .

Answer

1,2,4 1,2,4