A rectangle has a length (2x−5) and a width of (x−3) . What is the area of the rectangle?

2x² - 11x + 15

Step-by-step explanation:

Find the area of the rectangle by multiplying the length and width together, using FOIL

(2x - 5)(x - 3)

Multiply the first terms:

(2x)(x) = 2x²

Multiply the first term in the parentheses by the last term in the second set of parentheses:

(2x)(-3) = -6x

Multiply the second term in the first set of parentheses by the first term in the second set:

(-5)(x) = -5x

Multiply the last terms:

(-5)(-3) = 15

Add these all together, then add like terms

2x² - 6x - 5x + 15

2x² - 11x + 15

So, the area of the rectangle is 2x² - 11x + 15

the value of x is 9 ⇒ answer b

step-by-step explanation:

* we can solve this problem using cosine and sine rule

- in δ abc

∵ ab = 36 , bc = 28 , ac = 16

- lets find the measure of angle b using the cosine rule

∵ cos b = [ab² + bc² - ac²]/2(ab)(bc)

∴ cos b = [36² + 28² - 16²]/2(36)(28)

∴ cos b = 19/21

∴ m∠b = cos^-1(19/21) ≅ 25°

- lets find the measure of angle a using the sine rule

∵ sina/bc = sinb/ac = sinc/ab

∴ sina/28 = sin25°/16 ⇒ by using cross multiplication

∴ sina = 28 × sin25°/16

∴ sina = 0.7396

∴ m∠a = sin^-1(0.7396) ≅ 48°

- from the figure m∠abd = m∠dbc

∵ m∠abc = 25°

∴ m∠abd = 25°/2 = 12.5°

- in δabd

∵ m∠a = 48° , m∠abd = 12.5°

∵ the sum of the measures of the interior angles of any δ is 180°

∴ m∠adb = 180° - (48° + 12.5°) = 119.5°

∵ ab = 36

∵ ad = x

- use the sine rule to find x

∵ sin∠adb/ab = sin∠abd/x

∴ sin119.5°/36 = sin12.5°/x ⇒ by using cross multiplication

∴ x = 36 × sin12.5°/sin119.5° = 8.95 ≅ 9

* the value of x is 9