Answer:
62,5721
Step-by-step explanation:
12,01 × 5,21
= 62,5721
-x+3x=2x
2x=2+6
2x=8
8/2=4
x=4
Answer:
3x + 30
Step-by-step explanation:

3x + 30 would be an equivalent expression.
Hope this helps.
False is the correct answer
We will use double angle identities:
cos (5x ) = sin (10x )
cos (5x ) = 2 cos (5x ) sin ( 5x )
cos ( 5 x) - 2 cos ( 5 x ) sin ( 5x ) = 0
cos ( 5 x ) · [ 1 - 2 sin (5 x) ] = 0
cos ( 5 x ) = 0 or : 1 - 2 sin (5 x) = 0
5 x = π/2 +kπ, k∈Z sin (5 x) = 1/2
x1 = π/10 + kπ/5 5 x = π/6+2kπ , k∈ Z
5 x = 5π/6 +2kπ , k∈ Z
x 2 = π/30 +2kπ/5
x 3 = π/9 + 2kπ/5