(3x+4)(x - 2)
If you expand this out...
The 3x has to be multiplied by both elements in the second bracket
The 4 must also be multiplied by both elements in the second bracket
(3x)(x) -2(3x) +4(x) +4(-2)
= 3x^2 -6x +4x - 8
Then you have to collect like terms (the x's)
= 3x^2 - 2x - 8
You really have to watch the signs :) Just hold onto the sign in front of the parts and pieces you are working with...
YOUR TURN...
Can I have some help please.
4. (3x+4)(x - 2)
A. 3x^2-2x-8
B. x-8
C. 3x-2x-8
D. 3x^2+2x+8
5. (2y-1)(4y-3)
A. -2y+3
B. 8y^2-10y-3
C. 8y^2-10y+3
D. 8y^2-2y+3
3 answers
....and by the way, Google distributive property of multiplication
for example:
http://www.math-worksheet.org/multiplying
the way I think of it is
(a+b+c)(d+e+f)
=
a(d+e+f) +b(d+e+f) +c(d+e+f)
= ad+ae+af+bd+ ....... get it :)
for example:
http://www.math-worksheet.org/multiplying
the way I think of it is
(a+b+c)(d+e+f)
=
a(d+e+f) +b(d+e+f) +c(d+e+f)
= ad+ae+af+bd+ ....... get it :)
yes I get it Thank you :)