1. Determine the 10th and 21st terms of each of the following arithmetic sequences

a) 7;10;13;.....

b) 2;[tex] - \frac{1}{2} [/tex];-3;...​

c) 4+7x ; 5+9x + 6+11x ;....

d) a= -2 ; Term(5)=18

e) a=5; Term(4)=4

Respuesta :

Step-by-step explanation:

a. The rule is to add 3 to each corresponding term.

Multiply 3 by 9 and 20, then add to 7;

[tex]3 \times 9=27+7=34 \checkmark[/tex]

[tex]3\times20=60+7=67 \checkmark[/tex]

b. The rule is to subtract [tex]-2\frac{1}{2}[/tex].

Multiply [tex]-2\frac{1}{2}[/tex] by 9 and 20, then add 2;

[tex]-2\frac{1}{2} \times 9=-22\frac{1}{2}+2=-20\frac{1}{2} \checkmark[/tex]

[tex]-2\frac{1}{2} \times 20=-50+2=-48 \checkmark[/tex]

c. The rule is to add 1 to the whole number and add 2x to the coefficient.

Multiply 1 and 2x by 9 and 20, then add 4 and 7x;

[tex]1\times9=9+4=13\\2x\times9=18x+7x=23x\\13+23x \checkmark[/tex]

[tex]1\times20=20+4=24\\2x\times20=40x+7x=47x\\24+47x \checkmark[/tex]

d. The first term is -2, and the rule is to multiply by [tex]3\frac{3}{5}[/tex].

Multiply [tex]3\frac{3}{5}[/tex] by 9 and 20, then subtract 2;

[tex]3\frac{3}{5} \times 9 =32\frac{2}{5}-2=30\frac{2}{5} \checkmark[/tex]

[tex]3\frac{3}{5} \times 20=72-2=70 \checkmark[/tex]

e. The first term is 5, and the rule is to multiply by 1.

10th and 21st terms: [tex]5 \checkmark[/tex]