We are to verify the identity:
cos(α-B)-cos(α+B) = 2 sinα sinβ
Left hand side = cos(α - B)-cos(α + B)
= cosα cosβ + sinα sinB - (cosα cosB - sinα sinβ)
= cosα cosβ + sinα sinB - cosα cosB + sinα sinβ)
= sinα sinβ + sinα sinβ
= 2 sinα sinβ
= Right Hand side
The equation would be 40+15p=70+5p. You would subtract 5p from each side (15-5) and (5-5) and you'll have 40+10p=70. You would then subtract 40 from each side (70-40) and (40-40) to have 10p=30. You would divide by both of the sides by 10, you would end up with p=3. P is price training. The reason you divide and subtract on both sides is because you want the months to be on one side and the price training on the other side.
The answer is Thursday and Sunday hope this helps :D
.1 meters/1 second = 5 meters/ x seconds
cross multiply
.1x= 5
solve for x, (divide 1 on both sides)
50 seconds= x