How do combine like terms 3[x plus 3y] minus 5[x minus y?

3(x + 3y) - 5(x-7)

Use the distributive prop. to simplify

3x + 9y - 5x - 35

Use The assoc. prop to move them around.

3x - 5x + 9y - 35

combine like terms

-2x + 9y - 35

proportions are fractions that equal to each other. so if two fractions are the same, they are proportional.

let's check the answers to see if they are proportional.

question a is not proportional because you can't turn 1.5/3 to 3/9. if you try to multiply 1.5/3 by 2 or 3, you wont get 3/9. it's impossible to make the fractions the same.

question b is not proportional because you can't turn 22/33 to 4/6. 33 can't go into 6.

question c is proportional because when you multiply 2 and 3 by 71, you would get 142/213, and those fractions equal to each other

question d is proportional because when you divide 14 and 7 by 2, you would end up with 7/3.5, and those fractions equal to each other.