Corinne is 6 years younger than her brother. which of the following expressions shows the sum of their ages if b represents corinne's brother's age?
a) b − 6
b) 2b − 6
c) 2(b − 6)
d) b ÷ 6

Idon’t understand this.. will someone ? will mark brainliest along with 20 points.

Im gonna fail 7th grade selective breeding 1. creates offspring which are genetically identical to the parent 2. is the process of breeding only organisms with desirable traits 3. involves the removal of the nucleus of a cell 4. combines traits from organisms of different species

The figure below shows rectangle abcd and the triangle eca on a coordinate plane.which of the following expressions represents the perimeter of triangle of triangle eca in units