D. The combined expenses In Year 3 and 4 were $300,000 more than the combined of Year 3 and 4
Answer:
Step-by-stepapex answer to the left of 9.9 and to the right of 9.3 explanation:
<h3>Equation : x + y = 170 and y = 2x - 40</h3><h3>The weight of Bill is 70 pounds and weight of mark is 100 pounds</h3>
<em><u>Solution:</u></em>
Let the weight of Bill be "x"
Let the weight of mark be "y"
Given that,
Mark and Bill have a combined weight of 170 pounds
Therefore,
x + y = 170 ------- eqn 1
Mark weighs 40 pounds less than twice Bill's weight
y = 2x - 40 ------- eqn 2
<em><u>Substitute eqn 2 in eqn 1</u></em>
x + 2x - 40 = 170
3x = 170 + 40
3x = 210
x = 70
<em><u>Substitute x = 70 in eqn 2</u></em>
y = 2(70) - 40
y = 140 - 40
y = 100
Thus weight of Bill is 70 pounds and weight of mark is 100 pounds
All you have to do is plug in 3
Double-angle formulas:
2sinФcosФ=sin(2Ф) /:2
sinФcosФ=1/2*sin(2Ф)
sin(Ф/6)cos(Ф/6)=1/2*sin(2*Ф/6)=1/2*sin(Ф/3)
cos²Ф-sin²Ф=cos(2Ф)/*7
7cos²Ф-7sin²Ф=7cos(2Ф)
7cos²(Ф/9)-7sin²(Ф/9)=7cos(2*Ф/9)=7cos(2Ф/9)