Factorise x2 + 13x + 42

Mathematics

1 answer:

kirill [66]3 years ago

8 0

Answer:

you can use the formula "Cross method" in which the last number of the equation is the sum of 2 number multiplication that also sums the 2nd num of the equation.

so it becomes

(x +6)(x +7)

WHY?

Bcs when u multiply 6 x 7 = 42 ( the last number of the equation)

when u sum 6 + 7 = 13 ( the 2nd number of the equation)

Hope this helps :)

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aalyn [17]

Answer:

1. Rectangle

2. 376.8 cm

3. 379.94 square feet

4. –4 and 4

Step-by-step explanation:

A square is always a rectangle.

If a wheel has a radius of 15 cm, it would travel approximately 376.8 cm per 4 revolutions.

If the diameter of a circular garden is 22 feet, the approximate area of the garden is 379.94 square feet.

The solutions to the equation y2 – 1 = 15 is –4 and 4.

3 0

3 years ago

Read 2 more answers

The perimeter of an isosceles triangle is 65 centimeters. Find the length of the two equal sides when each is 10 centimeters lon

natita [175]

Answer: the length of each of the two equal sides is 25 centimeters

Step-by-step explanation:

Let x represent the length of each of the two equal sides. This means that the total length of the two longer sides is 2x.

Let y represent the length of the third side.

The perimeter of a triangle is expressed as the sum of the length of each side of the triangle. The perimeter of the isosceles triangle is 65 centimeters. It means that

2x + y = 65 - - - - - - - - - 1

Each of the equal sides is 10 centimeters longer than the third side. This means that

x = y + 10

Substituting x = y + 10 into equation 1, it becomes

2(y + 10) + y = 65

2y + 20 + y = 65

2y + y = 65 - 20

3y = 45

y = 45/3 = 15

Substituting y = 15 into x = y + 10, it becomes

x = 15 + 10 = 25

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