Question

Can someone please help me with these 3 questions and help me check my work?

Answer 1

18.
`x = 8`

19.
`c = 9`

20.
`d = √(10)`

21. 83 1/3 ft

22.

a. decay

b. growth

c. decay

Explanation:

18.

`√(x + 1) + 12 + 10 = 25`

[tex[ \sqrt{x + 1} = 3 [/tex]

Square both sides.

`x + 1 = 9`

`x = 8`

19.

`a^2 + b^2 = c^2`

`(√(75))^2 + (√(6))^2 = c^2`

`75 + 6 = c^2`

`81 = c^2`

`c = 9`

20.

`d = √((x_2 - x_1)^2 + (y_2 - y_1)^2)`

`d = √((3 - 4)^2 + (-9 - (-6))^2)`

`d = √((-1)^2 + (-3)^2)`

`d = √(1 + 9)`

`d = √(10)`

21.

Max: 5 ft tall; 3 ft shadow

Building: x ft tall; 50 ft shadow

5 ft is to 3 ft as x ft is to 50 ft

5/3 = x/50

3x = 250

x = 250/3

x = 83 1/3

Answer: 83 1/3 ft

22.

Exponential function:

y = a(b)^x

b is the number in parentheses raised to exponent x.

If b > 1, it is growth.

If b is between 0 and 1, it is decay.

Look at each case.

a. 0.85 is between 0 and 1: decay

b. 1.025 > 1: growth

c. 0.682 is between 0 and 1: decay