1 month: $3. Second: 3+3(2)=9. Third: 9+6(2)=21. Fourth: 21+12(2)=65. Fifth: 65+24(2)=113. In 5 months he would have saved $113 since he only needs $90 the answer is 5 :)
Answer:
622,080
Step-by-step explanation:
The total number of subjects is 3
= 3×2×1
= 6
Six maths book
= 6×5×4×3×2×1
= 720
Four physics book
= 4×3×2×1
= 24
Three chemistry book
= 3×2×1
= 6
6×720×24×6
= 622,080
Hence if the books are grouped together 622,080 arrangement is possible
I added a screenshot with the head of the question
Answer:sin (140°)
Explanation:Angle addition formulas are used to express the trigonometric function in terms of the sum/difference between two angles α and β
These rules are shown in the attached image.
Now, the given expression is::
sin97°cos43°+cos97°sin43°We have:
α = 97°
β = 43°
Comparing the given formula with the general formulas in the image, we would find that the given formula represents the sum of the sin of two angles.
Therefore:
sin97°cos43°+cos97°sin43°
= sin (97°+43°)
= sin (140°)
Hope this helps :)