Answer: -1.71
7(x+3) = 9 is the equation
7x+21 = 9
7x = -12
x= -12/7
x= -1.71
Answer:
Equation Notation
Step-by-step explanation:
Remember "SOH CAH TOA"
Sine = (Opposite/Hypotenuse)
Cosine = (Adjacent/Hypotenuse)
Tangent = (Opposite/Adjacent)
In this case, we will be using cosine, and our equation will be 
So firstly, cross-multiply. 
Next, divide both sides by cos(28), and your answer will be 
2 is your answer .........
Answer:the horizontal displacement is 34.64 meters
The maximum height is 15 meters
Step-by-step explanation:
As the ball moves from the ground at 30 degrees, it travels through a parabolic path. It can therefore be likened to a projectile. The horizontal displacement to where it lands is the range. The formula for determining range,R is
R = U^2Sin2#)/g
Where
U represents the initial velocity of the ball
g is acceleration due to gravity
# represents the angle above the horizontal.
From the information given
# = 30 degrees
U = 20 m/s
g = 10m/s^2
R = 20^2Sin2×30)/10 = (400Sin60)/20 = (400×0.8660)/10
= 34.64 meters
To determine the maximum height of the ball, H,
H = (U^2Sin^2#)/2g
H = (20^2 × Sin^2 30)/2×10
H = (400 × 0.866^2)/20 = 15 meters