Aim; How do we solve proportions by using cross product.?
1.)Explain; how the term cross product can help you remember how to solve a product.?
Fists you cross multiply.
Second you find the variable.
2.)Describe; the error in these steps: 2/3= x/12; 2x=36; x=18
First; They cross multiply wrong: 2(12)=24
Second; He had to put 3x=24: you had to divide 3÷24 and the answer would be x=8
3.)Show; how to use cross product to decide whether the ratios 6:45 and 2:15 are proportional.
You have to cross multiply 6(15)=90 and 45(2)=90
It has the same sum, so it is proportional.