Question

Simplify the expression 2(a + ab + 3) - ab and find its value when a = 5 and b = - 3.

• A. a + ab + 6 and 1
• B. 2a + 2ab + 6 and - 1
• C. 2a + ab + 6 and - 1
• D. 2a + ab + 6 and 1

Answer 1

The correct option is D 2a + ab + 6 and 1

2(a + ab + 3) - ab
= 2a + 2ab + 6 - ab
= 2a +( 2ab - ab) + 6
= 2a + ab + 6
Substituting a = 5, b = - 3 in the above expression,
= 2(5) + (5)(-3) + 6
= 10 - 15 + 6
= 16 - 15
= 1