emmaemp
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# Answer: a) -3+-2   b) 6 - -5   c) -3 x 9  d) 2x (x+6)  e) In a necklace the ratio of yellow beads to blue beads is 3:1. What percentage of the beads are yellow?  f) 3 (2x - 1) = 21   g)  Match these sequences to their algebraic expression: i) 4, 6, 8, 10, ...     ii) 7, 10, 13, 16, ... iii) 2, 5, 8, 11, ... iv) 3n   1  iiv) 2n    2    iiiv) 3n   4

$(-)+(+)=(-)$ $(-)+(-)=(+)$ $a)-3+(-2)= -3-2=-5$  $b)6-(-5)= 6+5=11$  $c)-3*9= -18$  $d)2x(x+6)=2x^{2}+12x$ $2x^{2}+12x=0$ Δ$=b^{2}-4ac$ in this case: $a=2$ $b=12$ $c=0$ so: Δ$=2^{2}-(4*12*0)$ Δ$=4-0$ Δ$=4$ $\sqrt{}$Δ=2 $x_{1}= \frac{-12-2}{2*2}=\frac{-14}{4}=\frac{-7}{2}=-3\frac{1}{2}$ $x_{2}= \frac{-12+2}{2*2}=\frac{-10}{4}=\frac{-5}{2}=-2\frac{1}{2}$ e) total amount of beads in this neclace is "4" so: $\frac{3}{4}*100$%$=\frac{3*100}{4}$%$=75$ $f)3(2x-1)=21$ $6x-3=21$ $6x=21+3$ $6x=24$ $x=4$ 1. $4, 6, 8, 10, ... =2n+2$ for example: $n=1$ $2*1+2=4$ $n=2$ $2*2+2=6$ etc. 2. $7, 10, 13, 16, ...=3n+4$ for example: $n=1$ $3*1+4=7$ $n=2$ $3*2+4=10$ etc. 3. $2, 5, 8, 11, ...=3n-1$ for example: $n=1$ $3*1-1=2$ $n=2$ $3*2-1=5$ etc.