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4 years ago

9

Hi right now im doing homework about common denominators and for some reason I cant understand how to do it

2 answers:

goldenfox [79]4 years ago

6 0

It would be great if you added some more details, but for common denominators you try to find the least common number that the 2 or more of the numbers you got have!
For example:
1/2 and 2/3 if you multiply 2 by 3 and 3 by 2, they both are 6, so you would multiply 1/2 both by 3 to make it into 3/6 and 2/3 by 2 to make it into 4/6!

Irina18 [472]4 years ago

6 0

Basically you have to find the lcm for the common denominator so that you can add/subtract them

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Write the inequality represents the verbal expression-<br> All real numbers less than 69

Lorico [155]

Let be M the set of the real numbers less thant 69

so we write it as follow M = { x∈R / x ∠ 69}

7 0

3 years ago

Write the equation of the parabola that has its x-intercepts at (1+<img src="https://tex.z-dn.net/?f=%5Csqrt%7B5%7D" id="TexForm

VladimirAG [237]

Answer:

$y=2x^2-4x-8$

Step-by-step explanation:

<u>Factored form of a parabola</u>

$y=a(x-p)(x-q)$

where:

p and q are the x-intercepts.
a is some constant.

Given x-intercepts:

(1+√5, 0)
(1-√5, 0)

Therefore:

$\implies y=a(x-(1+\sqrt{5}))(x-(1-\sqrt{5}))$

$\implies y=a(x-1-\sqrt{5})(x-1+\sqrt{5})$

To find a, substitute the given point (4, 8) into the equation and solve for a:

$\implies a(4-1-\sqrt{5})(4-1+\sqrt{5})=8$

$\implies a(3-\sqrt{5})(3+\sqrt{5})=8$

$\implies4a=8$

$\implies a=2$

Therefore, the equation of the parabola in factored form is:

$\implies y=2(x-1-\sqrt{5})(x-1+\sqrt{5})$

Expand so that the equation is in standard form:

$\implies y=2(x^2-x+\sqrt{5}x-x+1-\sqrt{5}-\sqrt{5}x+\sqrt{5}-5)$

$\implies y=2(x^2-x-x+\sqrt{5}x-\sqrt{5}x+\sqrt{5}-\sqrt{5}+1-5)$

$\implies y=2(x^2-2x-4)$

$\implies y=2x^2-4x-8$

6 0

2 years ago

Two friends practice taekwondo in the same class. The age of the older friend is three times that of the younger. The sum of the

vampirchik [111]

Answer:

4 and 12

Step-by-step explanation:

a = young

b = old

b = 3a, a+b =2a+8 => a = 4, b = 12

6 0

3 years ago

Debbie launched a toy rocket off a hill next to Lake Lakewood. The height h of the rocket in feet above the surface of the lake

jenyasd209 [6]

Answer:

t = 8.69 s

Step-by-step explanation:

The height h of the rocket in feet above the surface of the lake can be modeled by :

$h=340+100t-16t^2$

Let we need to find the time to reach the ground. When it reach the ground, h = 0

$340+100t-16t^2=0$

We need to find the value of t.

t = 8.69 s and -2.45 s

Neglecting negative value,

t = 8.69 s

Hence, it will take 8.69 s to reach the ground.

5 0

3 years ago

Erin buys 4 packs of potatoes costing £2 each, 2 packs of carrots for £3 per pack, and 5 turnips costing 70p each.

docker41 [41]

She would get £2.50

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2 times 3 is 6
0.7 times 5 is 3.5
Add them together
Minus it from 20
It equals £2.50

8 0

3 years ago