The reflection across the x-axis only change the signal of the y coordinate. Hence, the new point is

.
Answer:
50kg
Step-by-step explanation:
K = Keith B = Beth H = Henry
K = 20 + B
H = 2B - 30
K = H
20 + B = 2B - 30
B = 50kg
Distribute to eliminate the parenthesis
x^2 + 2x + 6x + 12 = 60
Combine like terms
x^2 + 8x + 12 = 60
Subtract 60 from both sides
x^2 + 8x - 48 = 0
Factor the equation
(x+12)(x-4)=0
x+12=0
x+4=0
x= -12 and -4