5th Year Project Math HL

kerryked

Right lads, first day of 5th year Honours Maths (the new syllabus) and I'm screwed!! Anyone willing to solve this problem for me and explain it?...I gave it a go and came up with a crazy answer altogether..about 7 terms altogether..I'm now starting to dread the thoughts of the rest of the new course if its gonna be like this.....
Anyways heres the problem;

(a+b)(x+5)^2

Cheers anyone who helps

Canard

I'm a little confused as to which part is being squared, but I'll assume its just the second bracket and have a go at it.

(a+b)(x+5)^2
(a+b)[(x+5)(x+5)]
(a+b)[x^2 + 10x + 25]
ax^2 + 10xa + 25a + bx^2 +10bx + 25b

Uhh..I'm not sure where to go from there What I'd normally do now is factorise but this is like the opposite of that. So your "about 7 terms" might be correct. :P

Apocladagr0

Looks like a weird question, not sure what you're asked to do
Also we cant solve expressions, only equations.

The whole thing would have to equal 0 for us to be able to solve it.

kerryked

hey guys thanks for the help..sorry i said 'solve'..the actual question was 'expand and simplify'..what i thought was being squared was the whole thing, but after reading your answers, maybe its just the second part?!...I guess I'll just write down the two different methods and ask the teacher when I go back on monday..she's a dragon though so I might just keep my head down and say nothing :P
also she told us to learn some formula off by heart..
x(y+z)= xy + xz..
(a+b)(a-b)= a^2-b^2
etc etc..do these really need to be learned off? I'm trying to figure out if she was being serious or just trying to scare us into the ordinary level class?..

Apocladagr0

kerryked wrote: »

hey guys thanks for the help..sorry i said 'solve'..the actual question was 'expand and simplify'..what i thought was being squared was the whole thing, but after reading your answers, maybe its just the second part?!...I guess I'll just write down the two different methods and ask the teacher when I go back on monday..she's a dragon though so I might just keep my head down and say nothing :P
also she told us to learn some formula off by heart..
x(y+z)= xy + xz..
(a+b)(a-b)= a^2-b^2
etc etc..do these really need to be learned off? I'm trying to figure out if she was being serious or just trying to scare us into the ordinary level class?..

Not trying to be mean but multiplying out brackets and the "difference of two squares" should be second nature;)

Canard

Yeah they're not so much formulas as logical steps to follow. Learn the difference of two cubes and try to understand it, it's a bit trickier but comes in handy.

pajero12

kerryked wrote: »

hey guys thanks for the help..sorry i said 'solve'..the actual question was 'expand and simplify'..what i thought was being squared was the whole thing, but after reading your answers, maybe its just the second part?!...I guess I'll just write down the two different methods and ask the teacher when I go back on monday..she's a dragon though so I might just keep my head down and say nothing :P
also she told us to learn some formula off by heart..
x(y+z)= xy + xz..
(a+b)(a-b)= a^2-b^2
etc etc..do these really need to be learned off? I'm trying to figure out if she was being serious or just trying to scare us into the ordinary level class?..

Think you'll be hard pressed to find a teacher who tries to scare you into the ordinary level class!