So 70 students had bought lunch because 70% of 100 is 70. Now take away 60% of that and you get 42.
Answer:
6v+8
Step-by-step explanation:
you multiply the equation in parantheses by 2
x = 9.21° or x = 22.5°
cot²2x – 4cot2x + 3 = 0
Let cot2x = y
y² - 4y + 3 = 0
Factorizing, we have
y² - y - 3y + 3 = 0
y(y - 1) -3(y - 1) = 0
(y - 1)(y - 3) = 0
y - 1 = 0 or y - 3 = 0
y = 1 or y = 3
Since cot2x = y
cot2x = 1 or cot2x = 3
1/tan2x = 1 or 1/tan2x = 3
tan2x = 1 or tan2x = 1/3
2x = tan⁻¹(1) or 2x = tan⁻¹(1/3)
2x = 45° or 2x = 18.43°
x = 45°/2 or x = 18.43°/2
x = 22.5° or x = 9.21°
So, x = 9.21° or x = 22.5°
Learn more about cotx here:
brainly.com/question/15546709
Step-by-step explanation:
x cos θ + y sin θ = x cos β + y sin β
<em>Let's say x = cos A, and y = sin A.</em>
cos A cos θ + sin A sin θ = cos A cos β + sin A sin β
<em>Use angle sum formula.</em>
cos(A − θ) = cos(A − β)
A − θ = ±(A − β)
A − θ = β − A
2A = θ + β
A = (θ + β) / 2
cot A = cot((θ + β) / 2)
x/y = cot((θ + β) / 2)
Answer: Mrs, William takes 18 treats to school.
Step-by-step explanation:
Given: When the crispy treats have cooled Mrs. Williams cut theme into 30 equal pieces .
She give 2/5 to her son, then the number of treats ahe give to her son = 
Then, the number of treats Mrs. Williams take to school =
Hence, Mrs, William takes 18 treats to school.