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2 years ago

(b) Factorise a² + 15a + 36

Mathematics

2 answers:

solmaris [256]2 years ago

5 0

(a+12)(a+3) should be right

ladessa [460]2 years ago

3 0

Answer: Hi

(a+3) (a+12)

Step-by-step explanation:

i hope this helps^_^

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Can someone explain this to me:)

Ostrovityanka [42]

Answer:

B) m = 2 , b = -3

Step-by-step explanation:

b = y-intercept

The y-intercept is -3

b = -3

m = slope

The slope is 2

m = 2

7 0

2 years ago

Read 2 more answers

A rectangle has an area of 130m2.

leonid [27]

Answer:

Step-by-step explanation:

7 0

2 years ago

Which is the solution set of 7y +1> 8y- 9?

fomenos

Answer:

y < 10 or (10, -∞)

Step-by-step explanation:

7y + 1 > 8y - 9

Simply get the y's on the right by subtracting 7y from both sides:

1 > y - 9

then adding 9 to both sides:

y < 10

or in interval notation:

(10, -∞)

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2 years ago

Find the approximate area between the curve f(x) = -4x² + 32x and on the x-axis on the interval [0,8] using 4 rectangles. Use th

Doss [256]

Split up the interval [0, 8] into 4 equally spaced subintervals:

[0, 2], [2, 4], [4, 6], [6, 8]

Take the right endpoints, which form the arithmetic sequence

$r_i=2+\dfrac{8-0}4(i-1)=2i$

where 1 ≤ <em>i</em> ≤ 4.

Find the values of the function at these endpoints:

$f(r_i)=-4{r_i}^2+32r_i=-16i^2+64i$

The area is given approximately by the Riemann sum,

$\displaystyle\int_0^8f(x)\,\mathrm dx\approx\sum_{i=1}^4f(r_i)\Delta x_i$

where $\Delta x_i=\frac{8-0}4=2$ ; so the area is approximately

$\displaystyle2\sum_{i=1}^4(-16i^2+64i)=-32\sum_{i=1}^4i^2+128\sum_{i=1}^4i=-32\cdot\frac{4\cdot5\cdot9}6+128\cdot\frac{4\cdot5}2=\boxed{320}$

where we use the formulas,

$\displaystyle\sum_{i=1}^ni=\frac{n(n+1)}2$

$\displaystyle\sum_{i=1}^ni^2=\frac{n(n+1)(2n+1)}6$

6 0

2 years ago

Use the Pythagorean Theorem to find an approximate value of x

kozerog [31]

Answer:

Step-by-step explanation:

Hypotenuse² =base² + altitude²

(3x + 4)² = (2x + 1)² + (3x)²

{Use (a+b)² = a² + 2ab + b²}

(3x)² + 2*3x+4 + 4² = (2x)² + 2*2x*1 + 1² + 9x²

9x² + 24x + 16 = 4x² + 4x + 1 + 9x²

9x² + 24x + 16 = 13x² + 4x + 1

0 = 13x² + 4x + 1 - 9x² - 24x - 16

13x² - 9x² + 4x - 24x +1 - 16 = 0

4x² - 20x - 15 = 0

a = 4 ; b =-20 ; c = -15

D = b² - 4ac = (-20)² - 4*4*(-15) = 400 + 240 = 640

√D = √640 = 25.30

$x=\dfrac{-b+\sqrt{D}}{2a} \ ; \ x=\dfrac{-b-\sqrt{D}}{2a}\\\\\\x=\dfrac{20+25.30}{2*4} \ ; \ x=\dfrac{20-25.30}{2*4}\\\\\\x=\dfrac{45.30}{8} \ ; \ x =\dfrac{-5.30}{8}\\\\$

x = 5 .66 ; x = -0.66

Ignore x = -0.66 as length of a side cannot be negative

Answer : x = 5.66

7 0

2 years ago