Question

In (x + 2) (3x + 1) = 3x^2 + ___ + 2, what should be the value of the middle term to complete the product?

Answer 1

Answer:

middle term = 7x

Step-by-step explanation:

in order to find the middle term, we will expand the bracket on the left hand side and compare the expressions on both sides.

(x + 2) (3x + 1) = 3x² + ___ + 2

let the unknown expression = y

(x + 2) (3x + 1) = 3x² + y + 2

Expanding the bracket on the left hand side by multiplication:

x + 2( 3x + 1) = (x × 3x) + (x × 1) + (2 × 3x) + ( 2 × 1)

= 3x² + x + 6x + 2

= 3x² + 7x + 2

Comparing with the expression on the right hand side:

3x² + 7x + 2 =  3x² + y + 2

∴ y = 7x

middle term = 7x