High School

20. If an AP has a first term of 6 and a last term of 54 with a common difference of 6, how many terms are there in the AP?
A. 8
B. 9
C. 10
D. 11

21. Where do the lines y = 2x + 3 and y = -x + 6 intersect?
A. (1, 5)
B. (2, 7)
C. (1, 4)
D. (3, 5)

22. Simplify log5 40
A. 2 - 2 log5 3
B. 1 - 2 log5 3
C. 1 + 3 log5 2
D. 2 + 3 log5 2

23. If f(x) = 3x + 2, what is f⁻¹(x)?
A. \frac{x-2}{3}
B. \frac{x+2}{3}
C. 3x - 2
D. \frac{3}{x+2}

24. Find the coefficient of the 4th term of the binomial expression (x – 3y)⁴
A. -12
B. 54
C. -108
D. 81

25. From the equation x² + y² + 6x - 8y + 9 = 0, find the radius.
A. 4
B. 5
C. 6
D. 7

26. What is the distance between the points (3, 4) and (7, 1)?
A. 5
B. -6
C. 25
D. -5

27. What is the range of the relation R = {(2, 5), (3, 7), (4, 5), (6, 8)}?

Answer :

Let's go through each of the math problems one by one:


  1. If an AP has a first term of 6 and a last term of 54 with a common difference of 6, how many terms are there in the AP?


The formula for the n-th term of an arithmetic progression (AP) is:

[tex]a_n = a_1 + (n-1) \cdot d[/tex]

Where:


  • [tex]a_n[/tex] is the n-th term

  • [tex]a_1[/tex] is the first term

  • [tex]d[/tex] is the common difference


Given:


  • [tex]a_1 = 6[/tex]

  • [tex]a_n = 54[/tex]

  • [tex]d = 6[/tex]


Plug these into the formula:

[tex]54 = 6 + (n-1) \cdot 6[/tex]

[tex]48 = (n-1) \cdot 6[/tex]

[tex]n-1 = \frac{48}{6}[/tex]

[tex]n-1 = 8[/tex]

[tex]n = 9[/tex]

Answer: B. 9


  1. Where do the lines [tex]y = 2x + 3[/tex] and [tex]y = -x + 6[/tex] intersect?


To find the intersection, set the equations equal:

[tex]2x + 3 = -x + 6[/tex]

Combine like terms:

[tex]2x + x = 6 - 3[/tex]

[tex]3x = 3[/tex]

[tex]x = 1[/tex]

Plug [tex]x = 1[/tex] back into one of the equations:

[tex]y = 2(1) + 3 = 5[/tex]

The intersection is at [tex](1, 5)[/tex].

Answer: A. (1, 5)


  1. Simplify [tex]\log_5 40[/tex]:


Express 40 as factors of 5 and 2:

[tex]40 = 5^1 \cdot 2^3[/tex]

Using logarithm properties:

[tex]\log_5 40 = \log_5 (5^1 \cdot 2^3)[/tex]

[tex]= \log_5 5^1 + \log_5 2^3[/tex]

[tex]= 1 + 3 \log_5 2[/tex]

Answer: C. 1 + 3 \log_5 2


  1. If [tex]f(x) = 3x + 2[/tex], what is [tex]f^{-1}(x)[/tex]?


To find the inverse, switch [tex]x[/tex] and [tex]f(x)[/tex]:


  1. [tex]y = 3x + 2[/tex]

  2. Switch [tex]x[/tex] and [tex]y[/tex]: [tex]x = 3y + 2[/tex]

  3. Solve for [tex]y[/tex]:
    [tex]x - 2 = 3y[/tex]
    [tex]y = \frac{x - 2}{3}[/tex]


Answer: A. \frac{x-2}{3}


  1. Find the coefficient of the 4th term of the binomial expression [tex](x - 3y)^4[/tex]:


Use the binomial theorem:

[tex](x - 3y)^4 = \sum_{k=0}^{4} \binom{4}{k} x^{4-k} (-3y)^k[/tex]

The 4th term corresponds to [tex]k = 3[/tex]:

[tex]\binom{4}{3} x^{1} (-3y)^3[/tex]

[tex]\binom{4}{3} = 4[/tex]

[tex](-3)^3 = -27[/tex]

[tex]\text{Coefficient} = 4 \times -27 = -108[/tex]

Answer: C. -108


  1. From the equation [tex]x^2 + y^2 + 6x - 8y + 9 = 0[/tex], find the radius.


Rearrange to form a circle equation:)

Complete the square:

[tex](x^2 + 6x) + (y^2 - 8y) = -9[/tex]

Complete the square for [tex]x[/tex]:

[tex]x^2 + 6x = (x+3)^2 - 9[/tex]

Complete the square for [tex]y[/tex]:

[tex]y^2 - 8y = (y-4)^2 - 16[/tex]

Substitute back:

[tex](x+3)^2 - 9 + (y-4)^2 - 16 = -9[/tex]

[tex](x+3)^2 + (y-4)^2 = 16[/tex]

The radius is [tex]\sqrt{16} = 4[/tex].

Answer: A. 4


  1. What is the distance between the points (3, 4) and (7, 1)?


Use the distance formula:

[tex]\text{Distance} = \sqrt{(x_2-x_1)^2 + (y_2-y_1)^2}[/tex]

[tex]= \sqrt{(7-3)^2 + (1-4)^2}[/tex]

[tex]= \sqrt{4^2 + (-3)^2}[/tex]

[tex]= \sqrt{16 + 9}[/tex]

[tex]= \sqrt{25}[/tex]

[tex]= 5[/tex]

Answer: A. 5


  1. What is the range of the relation [tex]R = \{(2, 5), (3, 7), (4, 5), (6, 8)\}[/tex]?


The range of a relation is the set of all second elements (y-values).

Thus, the range is [tex]\{5, 7, 8\}[/tex].