I have this mid term coming up, and I forgot how to do some of these. Please show me the steps of how to do it thanks.
1. 3(x+5)-7
2. 5(-x+12) +5(x-8)
Oh and also how do you know when to expand and simplify, or when to foil?
3. 3(2x+3y)(2x-3y)-2(3x-2y)² And the answer is -6x² + 24xy-35y²
1. 3(x+5)-7
2. 5(-x+12) +5(x-8)
Oh and also how do you know when to expand and simplify, or when to foil?
3. 3(2x+3y)(2x-3y)-2(3x-2y)² And the answer is -6x² + 24xy-35y²
-
when you have 3(x+5) you multiply 3 times each of the terms in the parentheses
when you have to binomials such as (2x+3y)(2x-3y) then you multiple the first term of the first binomial by each of the terms in the second binomial, then the second term of the first binomial by each of the terms in the second binomial. In other words you multiple each of terms by each other one time.
Check the link for an illustration
1. 3 times x is 3x, 3 times 5 is +15, result 3x + 15 - 7
2. same as above. Multiply 5 times -x and 5 times +12, then 5 times x and 5 times -8
3. Check the link on when to foil.
That should get you started.
when you have to binomials such as (2x+3y)(2x-3y) then you multiple the first term of the first binomial by each of the terms in the second binomial, then the second term of the first binomial by each of the terms in the second binomial. In other words you multiple each of terms by each other one time.
Check the link for an illustration
1. 3 times x is 3x, 3 times 5 is +15, result 3x + 15 - 7
2. same as above. Multiply 5 times -x and 5 times +12, then 5 times x and 5 times -8
3. Check the link on when to foil.
That should get you started.