Answer:
Step 3
Step-by-step explanation:
Given

Required:
Determine the first step where she made mistake
Her Step 1:
--- This is correct because she solved the bracket first
Her Step 2:
--- This is correct because she solved 3^2 as 9
Her Step 3:
--- This is incorrect because 23 * 4 is not equivalent to 9 * 4
Hence, her first mistake is in step 3.
The correct expression would have been

Then

Answer:
x = 8
Step-by-step explanation:
Equilateral triangle : congruent angles
3(7x+4) = 180
21x + 12 = 180
21x = 180-12
x = 168/21
x = 8
Answer:
The angle being shown is an acute angle
Step-by-step explanation:
The image of the given scenario is attached below.
A right angled triangle is formed, with one angle equal to 27 degrees. The perpendicular side is 155 and we are to find the length of guy wire which makes the hypotenuse of the right angled triangle.
Using the formula of sine, we can write:
Rounding to nearest whole number, the length of the guy wire that must be attached is 341 feet.