Answer:
64.5
Step-by-step explanation:
64.5
for an expression or relation to be a function, it must not have any x-coordinate values repeated, let's check this one

14.7x + 4x = 0*(49y+39y) y = 14
18.7x = 0(686 + 546)
18.7x = 0
x = 0
That is called square root
Answer:
D 21
Step-by-step explanation: x/7 = 3
isolate x by multiplyig both sides by 7: (7)(x/7) = (3)(7)
x = 21