Learn how to solve a proportion by applying the cross product ex 15, 15/(x+7) = 45/(x+21)

The video tutorial explains the process of using cross multiplication to solve equations with different denominators. It begins by identifying when cross multiplication is appropriate, then sets up the equation using the cross product. The tutorial emphasizes the importance of parentheses and the distributive property. It proceeds to solve the equation step by step, using a calculator for multiplication, and concludes by simplifying the equation to find the solution.

Why might cross multiplication be preferred over multiplying by the least common denominator?

• It is always faster.

• It avoids dealing with common factors.

• It requires fewer steps.

• It is more accurate.

What is the importance of using parentheses in cross multiplication?

• To separate different terms.

• To ensure the distributive property is applied correctly.

• To simplify the equation.

• To make the equation look neat.

What is the result of multiplying 15 by 21 in the example?

• 315

• 345

• 300

• 330

What is the next step after applying cross multiplication in solving the equation?

• Multiply both sides by a constant.

• Subtract the variables from both sides.

• Add the variables to both sides.

• Divide both sides by a constant.

What is the final solution for X in the given proportion?

• X = -1

• X = 2

• X = 0

• X = 1