15, explanation and answer

10 gallons of paint

Step-by-step explanation:

First, find the surface area of the monument.

From inspection, this is made up of 4 congruent rectangles and 4 congruent triangles.

Area of a rectangle = width x length

Therefore, area of one rectangle of the monument:

13 x 40 = 520 ft²

Area of triangle = 1/2 x base x height

Therefore, area of one triangle of the monument:

1/2 x 13 x 11 = 71.5 ft²

Therefore, total surface area of the monument

= 4 x SA of rectangle + 4 x SA of triangle

= 4 x 520 + 4 x 71.5

= 2080 + 286

= 2366 ft²

We are told that one gallon of paint can cover 239 ft², and that paint can only be bought by the gallon.

Divide the total surface area of the monument by the area one gallon of paint can cover to calculate how many cans of paint are needed.

2366 ÷ 239 = 9.89958159...

Therefore, 10 gallons of paint must be bought (since we need to round up as paint can only be bought by the gallon).

15

step-by-step explanation:

we are given the following expression and we are to solve it and find the product:

-13 × (-5)

solving the given expression in the standard order of solving a mathematical expression, beginning with the opening of brackets and then multiplying the terms and changing their signs.

-3 × -5 = 15 (answer is positive because when negative is multiplied with negative, it gives a positive answer)

option 3 . (5x + 1) - (-10x + 6)

step-by-step explanation:

option 1 :

(4x + 3) + (-9x + 4)

or 4x+3 -9x + 4

or -5x + 7

option 2

(x - 2) - (6x - 9)

or x-2-6x + 9

or -5x + 7

option 3

(5x+ + 6)

or 5x + 1 + 10x -6

or 15x -5

option 4

-4x+2x+7-3x

-7x + 2x + 7

-5x + 7

hence only option 3 did   not satisfy the given simplify expression.