Here the only limitation on the domain exists when the denominator is equal to zero, as division by zero has no meaning and is not "allowed" because of its meaninglessness. :)
Factor the denominator to find the excluded values of x...
3x^2+5x-12
3x^2+9x-4x-12
3x(x+3)-4(x+3)
(3x-4)(x+3)
So x CANNOT equal 4/3 or -3 (all other real values of x are part of the domain) so the domain is:
x=(-oo, -3),(-3, 4/3),(4/3, +oo)
Answer:
Step-by-step explanation:
Assuming the first part of this is "x squared" then just factor the trinomial by inspection
We set up the equation (70+64+83+x)/4=75
Multiply by 4 on both sides: 70+64+83+x=300
Combine like terms on left side: 217+x=300
Subtract 217 from both sides: x=83
So Sara must get at least an 83% in order to maintain a final average of 75%
Hope this helped!
