Pl .
a mason will lay rows of bricks to build a wall. the mason will spread 3/8
inch of mortar on top of all but the last row of bricks. the finished wall will be 1/8
inches less than 4 feet high. answer parts a and b below.
the mason wants to lay the bricks so that the shortest edge of each brick is vertical. how many rows of bricks are needed? show your work.
let b equal the number of rows of bricks. the total height of the bricks in inches is equal to times
the total height of the mortar is equal to times
their sum is equal to the height of the wall or inches.
if i write this as an equation and solve for b, then the result is of bricks

a) 18 rows of bricks are needed

b) 2.25 times b

0.375 times (b - 1)

46.875 inches

18 rows

Step-by-step explanation:

* Lets explain how to solve the problem

a)

- The height of each brick is the shortest edge

- The shortest age is 2 1/4 inch ⇒ (2.25 inches)

- If b is the number of the rows of bricks

∴ The height of the bricks = 2.35 × b

- The height of the mortar is 3/8 inches ⇒ (0.375 inch)

- All rows of bricks covered by mortar on top except the last row

- The height of mortar = 0.375 × (b - 1)

- The height of the wall is 1 1/8 (1.125) inches less than 4 feet

∵ 1 foot = 12 inches

∵ 4 feet = 12 × 4 = 48 inches

∴ The height of the wall = 48 - 1.125 = 46.875 inches

- The sum of the total height of bricks and the total height of mortar

 is equal to the height of the wall

∴ 2.25 b + 0.375(b - 1) = 46.875

- By simplify it

∴ 2.25 b + 0.375 b - 0.375 = 46.875

∴ 2.625 b - 0.375 = 46.875

- Add 0.375 for both sides

∴ 2.625 b = 47.25

- Divide both sides by 2.625

∴ b = 18

∴ 18 rows of bricks are needed

b)

* Lets complete the missing

- The total height of the bricks in inches is equal to 2.25 times b

- The total height of the mortar is equal to 0.375 times (b - 1)

-  Their sum is equal to the height of the wall or 46.875 inches

- If I write this as an equation and solve for b, then the result is

 18 rows of bricks

let's cover over the formula of the vertex:

y = a(x – h)^2 + k

in this formula, (h,k) are the vertex, always remember that the positive or negative value of the vertex is based on the sign it has.

for example, if the vertex is -3,-6 then both the x and y value would have the positive sign attached to it and if it were a positive x and y value, then a negative sign would be attached to it.

with that being said, for our problem the x value is a positive one so we are looking for a number with a negative sign next to it, in this case the first and second choice.

however, for the first answer choice it isn't quite part of the formula so we know that the answer choice correctly displays the x value.

to confirm, we can see if the -1 fits correctly with the second answer choice, and as mentioned above a negative number will have a positive sign attached to it. so, for our problem we can see that -1 has been changed to +1, so we can confirm that the second answer choice is correct.

hence, our final answer is y=(x - 1)^2 + 1

5=812a+9+3

step 1: simplify both sides of the equation.

5=812a+9+3

5=(812a)+(9+3)(combine like terms)

5=812a+12

5=812a+12

step 2: flip the equation.

812a+12=5

step 3: subtract 12 from both sides.

812a+12−12=5−12

812a=−7

step 4: divide both sides by 812.

812a /812 = -7/812

a= -1/116

so the answer is

a=   -1/116