# How do you use cross products to solve #3/4=x/(x+3)#?

By signing up, you agree to our Terms of Service and Privacy Policy

x = 9

distribute the bracket : 4x = 3x + 9

subtract 3x from both sides to solve for x

By signing up, you agree to our Terms of Service and Privacy Policy

This is why the cross product works!!!

The cross product is a shortcut that bypasses some stages in solving by first principles. I will use first principles so you can see where the shortcut takes over.

If you look at the numerators you will see the result you get by the short cut

By signing up, you agree to our Terms of Service and Privacy Policy

To solve ( \frac{3}{4} = \frac{x}{x+3} ) using cross products:

- Multiply both sides of the equation by ( x+3 ).
- This yields: ( 3(x+3) = 4x ).
- Expand and simplify the equation: ( 3x + 9 = 4x ).
- Subtract ( 3x ) from both sides: ( 9 = x ).

Therefore, ( x = 9 ).

By signing up, you agree to our Terms of Service and Privacy Policy

When evaluating a one-sided limit, you need to be careful when a quantity is approaching zero since its sign is different depending on which way it is approaching zero from. Let us look at some examples.

When evaluating a one-sided limit, you need to be careful when a quantity is approaching zero since its sign is different depending on which way it is approaching zero from. Let us look at some examples.

When evaluating a one-sided limit, you need to be careful when a quantity is approaching zero since its sign is different depending on which way it is approaching zero from. Let us look at some examples.

- How do you solve #0.4k + 0.4k - 0.02= 4.02#?
- When viewed under a light microscope, the size of the cell in the diagram was 20 mm. The magnification of the image was x400. What is the actual size of the cell and give your answer in um (micrometres)?
- How do you solve for x in #2x-a=b #?
- How do you solve #5x+6=2x+3-x#?
- How do you solve # 2/3x=6#?

- 98% accuracy study help
- Covers math, physics, chemistry, biology, and more
- Step-by-step, in-depth guides
- Readily available 24/7