Question

Nikki is building a wall for her garden with bricks. each brick is 10 inches long. the bricks are laid end-to-end, and one inch of mortar is layered between each brick.

write an equation to model the number of bricks,n, nikki needs in each layer to build a wall 10 feet long

Answer 1

`11n-1=120`

Explanation:

It is given that,

Length of each brick = 10 inches

Mortar between between each brick = 1 inch

For 2 bricks, we need mortar once.

For 3 bricks, we need mortar 2 times.

For 4 bricks, we need mortar 3 times.

Similarly,

For n bricks, we need mortar (n-1) times.

Total length of n bricks = 10n inches

Total length of (n-1) times mortar = 1(n-1) = n-1 inches

Total length of wall = 10n + (n-1) inches.

1 feet = 12 inches

10 feet = 120 inches

The equation to model the number of bricks,n, nikki needs in each layer to build a wall 10 feet long.

`10n+(n-1)=120`

`11n-1=120`

Therefore, the required equation is
`11n-1=120`.