Step-by-step explanation:
<u>Given</u>
- x + 2y = 3 and xy = 2
- show that x³ + 8y³ + 9 = 0
<u>Solution in steps:</u>
- (x + 2y)³ = 3³
- x³ + 3x²(2y) + 3x(2y)² + (2y)³ = 27
- x³ + 6x(xy) + 12y(xy) + 8y³ = 27
- x³ + 8y³ + 6(x + 2y)xy = 27 ⇒ Substitute values
- x³ + 8y³ + 6*3*2 = 27
- x³ + 8y³ + 36 - 27 = 0
- x³ + 8y³ + 9 = 0
Done
Answer: 24.5
Step-by-step explanation: 1cm/9.8 mi
2.5cm/? 2.5 *9.8= 24.5
Answer:
D last one.
Step-by-step explanation:
4x4=16 not 8
Answer:
Step-by-step explanation:
Remark
This is a cosine law problem.
a = 12
b = 15
C = 83
Notice that the angle is enclosed by 2 given sides. That's what a cosine problem looks like (one of the two choices.
Formula
c^2 = a^2 + b^2 - 2ab*cos(C)
Solution
c^2 = 12^2 + 15^2 - 2*12*15 * cos(83)
c^2 = 144 + 225 - 360 * cos(83)
cos(83) = 0.1219
c^2 = 144 + 225 - 360 * 0.1219
c^2 = 369 - 43.884
c^2 = 325.116
sqrt(c^2) = sqrt(325.116)
c = 18.031
To the nearest tenth, the answer is 18.0 and you must include the 0.
