7
QuizMultiple Choice
Cross Products
Question 7 • FL-1205040-M/J Grade 7 Mathematics A -GF
Joanie believes that you cannot use cross products to solve the proportion for x. She says that if you multiply both sides of the equation by x, you get . Then, if you multiply both sides of the equation by 3, you get , which is a different equation than you would get if you cross multiplied. What mistake did Joanie make in her reasoning?
Answer
A
She assumed that the multiplication property of equality allows her to multiply both sides of the equation by x.
B
She assumed that the multiplication property of equality allows her to multiply both sides of the equation by 3.
C
She assumed that is the equation that you get if you multiply both sides of the equation by 3.
D
She assumed that is the equation that you get if you multiply both sides of the equation by x.