What is 4x + 2 = 7x + 9

Mathematics

2 answers:

Free_Kalibri [48]3 years ago

8 0

4X=7X+7

-3X=7

X= -3/7

Over [174]3 years ago

8 0

Hi!

This question is about math.

$4x + 2 = 7x + 9$

First subtract 2 from both sides.

$4x+2-2=7x+9-2$

Then simplify.

$4x-7x=7x+7-7x$

Simplify again.

$-3x=7$

Divide both sides by -3

$\frac{-3x}{-3}=\frac{7}{-3}$

Simplify

$x=-\frac{7}{3}$

Hope this helps you. Thank you for posting your question at here on Brainly.

-Charlie

You might be interested in

Can someone pls tell me if this is correct? For the properties, <3 and the bottom one too

saul85 [17]

1. Commutative property of multiplication This is because it represents a*b=b*a
2. Associative property of multiplication. Multiplication problems end with the same product no matter the order of factors.
3. Correct
4. Correct
5. Associative property of addition. Even though the grouping symbols are different, it is equivalent because you are adding all the terms together.
6. Correct

The last one should also be associative property since it applies every time you combine like terms.
Just a reminder: Distributive property is only when you multiply in the form of a(b+c)=ab+ac

7 0

3 years ago

The mass of the particles that a river can transport is proportional to the sixth power of the speed of the river. A certain riv

kari74 [83]

The river flows at 2 miles per hour. This is the speed of the current, or the speed at which the water itself is moving.

The mass of the particles moving in river is proportional to the sixth power of 2, or $2^6 = 64$ miles per hour. So, if x is the mass of the particle, then the speed is modeled by an inverse relationship $x * 2^6 = k$ , for some constant k.

For particles that are 15 times the usual mass, the speed of the river itself must increase for the particles to travel at the same speed as before. The mass of the particles is still proportional to the sixth power of the speed of the river, but the speed of the river can no longer be 2 miles per hour. It is some speed y, which we are solving for.

So, the key here is proportional. We can set up two proportions and cross multiply.

$\dfrac{x}{2^6} = \dfrac{15x}{y^6} \\ (x)(y^6)=(2^6)(15x)$

Cancelling our x's (because we don't need to solve for them), we have

$y^6 = 15(2^6) = 15(64)=960$

To solve for y, we must take the sixth root of both sides, or raise both sides to the one-sixth power.

$\sqrt[6]{y^6} = \sqrt[6]{960}$

Using a calculator, we see that $\sqrt[6]{960} = 3.14 \ miles \ per \ hour$ .