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3 years ago

Select the expression that are equivalent to 7a+4a

Mathematics

1 answer:

TEA [102]3 years ago

3 0

Answer:

7a+4a

we add same term.

a is common for both.

First take common term out

7a+4a = a(7 + 4) (we add same term.

= 11a

Step-by-step explanation:

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What is the value of this expression 14−3? 164 112 12 64

Firlakuza [10]

Answer:

Step-by-step explanation:

14-3 = 11

you have 14 apples and you eat 3 of them. wow! now you have 11 apples!

4 0

3 years ago

If the sum of the zereos of the quadratic polynomial is 3x^2-(3k-2)x-(k-6) is equal to the product of the zereos, then find k?

lys-0071 [83]

Answer:

Step-by-step explanation:

So I'm going to use vieta's formula.

Let u and v the zeros of the given quadratic in ax^2+bx+c form.

By vieta's formula:

1) u+v=-b/a

2) uv=c/a

We are also given not by the formula but by this problem:

3) u+v=uv

If we plug 1) and 2) into 3) we get:

-b/a=c/a

Multiply both sides by a:

-b=c

Here we have:

a=3

b=-(3k-2)

c=-(k-6)

So we are solving

-b=c for k:

3k-2=-(k-6)

Distribute:

3k-2=-k+6

Add k on both sides:

4k-2=6

Add 2 on both side:

4k=8

Divide both sides by 4:

k=2

Let's check:

$3x^2-(3k-2)x-(k-6) \text{ with }k=2$ :

$3x^2-(3\cdot 2-2)x-(2-6)$

$3x^2-4x+4$

I'm going to solve $3x^2-4x+4=0$ for x using the quadratic formula:

$\frac{-b\pm \sqrt{b^2-4ac}}{2a}$

$\frac{4\pm \sqrt{(-4)^2-4(3)(4)}}{2(3)}$

$\frac{4\pm \sqrt{16-16(3)}}{6}$

$\frac{4\pm \sqrt{16}\sqrt{1-(3)}}{6}$

$\frac{4\pm 4\sqrt{-2}}{6}$

$\frac{2\pm 2\sqrt{-2}}{3}$

$\frac{2\pm 2i\sqrt{2}}{3}$

Let's see if uv=u+v holds.

$uv=\frac{2+2i\sqrt{2}}{3} \cdot \frac{2-2i\sqrt{2}}{3}$

Keep in mind you are multiplying conjugates:

$uv=\frac{1}{9}(4-4i^2(2))$

$uv=\frac{1}{9}(4+4(2))$

$uv=\frac{12}{9}=\frac{4}{3}$

Let's see what u+v is now:

$u+v=\frac{2+2i\sqrt{2}}{3}+\frac{2-2i\sqrt{2}}{3}$

$u+v=\frac{2}{3}+\frac{2}{3}=\frac{4}{3}$

We have confirmed uv=u+v for k=2.

4 0

2 years ago

Pls help me with this question!

Sveta_85 [38]

Step-by-step explanation:

<u>The inequality represents:</u>

h is less than or equal to 46.

<u>Values included;</u>

46
Values less than 46.

I apologize for the line being uneven.

7 0

2 years ago

Just the last two ones please and thank you if you awnsered this

Rudik [331]

Number 1 is twenty and number two is fifty six

8 0

3 years ago

In Nathan’s baseball card collection, 58% of cards are players from the National League. He has 702 baseball cards. About how ma

Bogdan [553]

Nathan has exactly 407 cards from national league however since you have to estimate with that rate the answer is 400.

702 (Total Cards) × 0.58 = 407. 16
407.16 (Rounded to 100) = 400

702 × 0.58 = 407.16 = 400

If you can please drop a follow it really makes my day anyways thanks~!

5 0

3 years ago

Select the expression that are equivalent to 7a+4a​

Select the expression that are equivalent to 7a+4a