Answer:
A: an = 6n - 9
Step-by-step explanation:
third term in an arithmetic sequence is 9
a3 = a + 2d
a + 2d = 9
the fifth term is 21
a5 = a + 4d
a + 4d = 21
a + 2d = 9 (1)
a + 4d = 21 (2)
Subtract (1) from (2) to eliminate a
4d - 2d = 21 - 9
2d = 12
d = 12/2
d = 6
Substitute d = 6 into (1)
a + 2d = 9 (1)
a + 2(6) = 9
a + 12 = 9
a = 9 - 12
a = -3
nth term of this sequence = a + (n - 1)d
= -3 + (n - 1)6
= -3 + 6n - 6
= 6n - 9
an = 6n - 9
Answer:
17 and 10
Step-by-step explanation:
Write the problem as an equation.
a+b=27
a=b-7
Where a and b are the two numbers you are trying to find. You could use any variables. Then solve.
b+(b-7)=27 Sub (b-7) for a
2b-7=27 Group like terms
2b=34 Add 7 to both sides
b=17 Divide both sides by 2.
Because b=17, a must be 10.
Answer:
it cost Jacob family $32 and he used 7 $5 bill to pay
Step-by-step explanation:
2 × 7 = 14
3 × 6 = 18
18 + 14 = 32
5x - 32 = 3
5x = 32 + 3
5x = 35
x = 35 ÷ 5
x = 7
Answer:
3.7 feet
Step-by-step explanation:
A golden rectangle is a rectangle in which the length and the width are in the ratio 1 : 1.618
If the width of the rectangle is 6, the length = 6 / 1.618 = 3.708 ft
= 3.7 (to the nearest tenth)
the tenth is the first number after the decimal place. To convert to the nearest tenth, look at the number after the tenth (the hundredth). If the number is greater or equal to 5, add 1 to the tenth figure. If this is not the case, add zero
For any point reflected in the y- axis
(x, y ) → (- x, y )
A(1, 1) → A'(- 1, 1)
B(5, 1 ) → B'(- 5, 1 )
C(3, 3 ) → C'(- 3, 3 )
