Divide botoh sides by 7
x-12=-3
add 12 to both sides
x+12-12=12-3
x+0=9
x=9
Answer:
sin⁴x - sin²x
sin²x(sin²x - 1)
(1 - cos²x)(1 - cos²x - 1)
(1 - cos²x)(-cos²x)
-cos²x + cos⁴x
cos⁴x - cos²x
Answer:
1. 10
2. 12
3. Sqrt 130
4. Sqrt 45
Step-by-step explanation:
To find the missing side of a right triangle, use the Pythagorean Theorem. The Pythagorean Theorem is 
where a and b are the legs with a being the smallest and c is the hypotenuse.
1. a=6, b=8, c=?
2. a=5, b=?, c=13
3. a=7, b=9, c=?
4. a=2, b=?, c=7
Answer: 18 (b)
Step-by-step explanation:
3x6=18
Answer:
45 degrees
Step-by-step explanation:
angle QRS is same as (2x + 3) because it is an isosceles triangle
so, 90 + (2x+3) + (2x+3) =180 degrees
2x+3 +2x+3=180-90
2x+2x +3+3=90
4x+6=90
4x=90-6
4x=84
x=84/4
x=21
substitute x=21 in (2x+3)
2*21+3=45
