Answer:
-3
Step-by-step explanation:
1. subtract 0.3 from both sides
2. add 3.7x to both sides
3. Divide both sides by -0.5
The top and bottom faces are 3 inches by 3 inches.
Area = 3 in. * 3 in. * 2 = 18 in.^2
The front, back, right, and left faces are 3 in. by 6 in.
Area = 3 in. * 6 in. * 4 = 72 in.^2
Total surface area = 18 in.^2 + 72 in.^2 = 90 in.^2
Answer: B. 90 square inches
The answer is D; could you make me the brainiest? Because the answer is 81m+27t
Answer:
6) -7 + 10 = 3 (3 more; total number doesn't matter)
7) 50w + 20
8) c / 5
9) 5 + 2t
10) 4d + 2d
I didn't see the trick problem!
Write the left side of the given expression as N/D, where
N = sinA - sin3A + sin5A - sin7A
D = cosA - cos3A - cos5A + cos7A
Therefore we want to show that N/D = cot2A.
We shall use these identities:
sin x - sin y = 2cos((x+y)/2)*sin((x-y)/2)
cos x - cos y = -2sin((x+y)/2)*sin((x-y)2)
N = -(sin7A - sinA) + sin5A - sin3A
= -2cos4A*sin3A + 2cos4A*sinA
= 2cos4A(sinA - sin3A)
= 2cos4A*2cos(2A)sin(-A)
= -4cos4A*cos2A*sinA
D = cos7A + cosA - (cos5A + cos3A)
= 2cos4A*cos3A - 2cos4A*cosA
= 2cos4A(cos3A - cosA)
= 2cos4A*(-2)sin2A*sinA
= -4cos4A*sin2A*sinA
Therefore
N/D = [-4cos4A*cos2A*sinA]/[-4cos4A*sin2A*sinA]
= cos2A/sin2A
= cot2A
This verifies the identity.
