Answer: Option d.
Step-by-step explanation:
The trigonometric identity needed is:

Knowing that
:
Substitute it into
:

Simplify the expression:

Solve for
. Apply square root at both sides of the expression:


Answer:
a=11
Step-by-step explanation:
Let's solve your equation step-by-step.
√a+5=4
Solve Square Root.
√a+5=4
a+5=42(Square both sides)
a+5=16
a+5−5=16−5(Subtract 5 from both sides)
a=11
Check answers. (Plug them in to make sure they work.)
a=11(Works in original equation)
Answer:
9 textbooks!
Step-by-step explanation:
Rucksack can hold = 6kg
Mass of textbook = 680g
So, here we need to show the division for finding the number of textbooks it can hold.
680 g in KG's = 0.68
Now, 6/0.68
That is 8.82 ( Round off = 9 textbooks)