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Current time:0:00Total duration:2:45

Writing expressions with variables & parentheses

Video transcript

first consider the expression four negative five plus the quantity of four times X now take the product of negative eight and that expression and then add six so let's do it step by step first we're going to have this expression negative five plus something so it's going to be negative five plus the quantity of four times X the quantity of four times X well that's just going to be 4x so it's going to be negative five plus 4x so that's this expression up here now take the product of negative eight so I'm going to take negative eight and we're going to multiply the product of negative eight and that expression so we're gonna take negative eight and multiply it so that expression is this thing that expression is this thing right over here so the product if we say the product of negative eight and that expression is going to be negative eight x times that expression that expression is negative five plus four X so that's negative eight that's that expression the product the product of the two the product of the two so we could put a multiplication sign there or we could just leave that out and implicit would mean multiplication take the product of negative eight and that expression and then add six so that's and then add six so that would be then adding six right over here so we could write it as negative eight open parenthesis negative five plus four X and then add six let's do one more first consider the expression the sum of seven the sum of seven and so that's going to be 7 plus something and the product of negative two and X the product of negative two and X is negative 2x negative 2x so 7 plus negative 2x we could write that as 7 minus 2x so this is equal to 7 minus 2x this these are the same expression what expression would be 4 plus so now we're saying 4 plus 4 plus the quantity of 2 times that expression so it's going to be 4 plus some quantity the four plus the quantity of put that in parentheses the quantity of two times do this in magenta of two times that expression or in yellow two times that expression that let me do this in blue that expression is this thing right over here so the four plus the quantity of two times that expression 2 times 7 minus 2x and we are done