when it doesnt lie between 1 and 10...move decimal so it does...add 1 to power number if if moved 1 place to left and take 1 off the power number if moved to the right.
example of standard form...17000000 = 1.7 x 10 to the power of 7
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expanding brackets
times everything outside of brackets by everything inside brackets...eg: 3(y+2) = 3y+6
Expand and simplify
eg: 3 (4+m) +2 (5+2m)
12+3m + 10+4m
= 22+7m
smiley face method!!! (x-4)(x+5)
first do ***= xsquared...then do X x 5 = 5x...then do 4 x X= 4x...finally do -4 x 5 = 20
so...xsquared+5x-4x-20
finally simplify the +5x-4x which = x...so the answer is...xsquared + x - 20
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Factorising
Factorising is the opposite to expanding.
EG... start with xsquared + 7x + 12...we need to get it into brackets!!!!!
find two numbers that times together to make the 12 and add together to make7
so (x+4) (x+3) is the answer
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Direct Proportion
EG...
T is proportional to M
If T=20 when M=4 find the following.......a) T when M=3 b)M when T=10
T is proportional to M
T = K x M.......20=Kx4....so k=5....then T=5xM
a) T=5xM.....T=5x3.....T=15
b) T=5xM.....10=5xM.....M=2
If it is squared then jsut add the square number in.
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