Answer:
D -24/25
Step-by-step explanation:
sin(2x) = 2sin(x)cos(x)
cos(x) = ⅘
sin²(x) = 1 - cos²(x) = 1 - (⅘)²
sin²(x) = 9/25
sin(x) = -⅗
(Because 4th quadrant)
sin(2x) = 2(-⅗)(⅘)
= -24/25
Answer:
-4x*2 - 7y*2 + 4
Step-by-step explanation:
simplify by adding/subtracting the like terms
Answer:
4x=289
Step-by-step explanation:
this expression could easily help find what the number is by 289/4
Answer:
-9, 9
Step-by-step explanation:
a² − 8ab + 16b² = 81
(a - 4b)² = 81 Wrote the left-hand side as a square
a - 4b = ±9 Took the square root of each side
All values of a - 4b are -9 and +9.
Ni : Zn: Cu = 7:2:9 =7x : 2x : 9x
7x+2x+9x = 3.8
18x=3.8
x=3.8/18=1.9/9≈0.21
Ni: 7x=7*0.21=1.47 ≈1.5 kg
Zn: 2x=2*0.21=0.42≈0.4 kg
Cu: 9x=9*0.21=1.89 ≈1.9 kg
Check 1.5+0.4+1.9 =3.8 True
