Answer:
{x=2,y=2
Step-by-step explanation:
Equation 1:
Multiply both sides of the equation by a coefficient
{ 4(2x-y)=2*4
-5x+4y=-2
Apply Multiplicative Distribution Law
{8x-4y=2*4,-5x+4y=-2
8x-4y+(-5x+4y)=8+(-2)
Remove parentheses
8x-4y-5x+4y=8-2
Cancel one variable
8x-5x=8-2
Combine like terms
3x=8-2
Calculate the sum or difference
3x=6
Divide both sides of the equation by the coefficient of the variable
x=6/3
Calculate the product or quotient
x=2
Equation two:
{-5+4y=-2, x=2
-5*2+4y=-2
Calculate the product or quotient
-10+4y =-2
Reduce the greatest common factor (GCF) on both sides of the equation
-5+2y=-1
Rearrange unknown terms to the left side of the equation
2y=-1+5
Calculate the sum or difference
2y=4
Divide both sides of the equation by the coefficient of the variable
y=4/2
y=2
Hope this helps!!
Answer:
$15.63 ≤ x ≤ $54.365
Step-by-step explanation:
Profit of the phone company is modeled by the equation,
p(x) = -50x² + 3500x - 2500
For the profit of at least $40000,
-50x² + 3500x - 2500 ≥ 40000
-50x² + 3500x ≥ 40000 + 2500
-50x² + 3500x ≥ 42500
-x² + 70x ≥ 850
x² - 70x + 850 ≤ 0
By quadratic formula,
x - intercept of the inequality will be,
x = 
x = 
x = 15.635, 54.365
Therefore, $15.635 ≤ x ≤ $54.365 will be the range of cost for which profit will be at least $40000.
If it has real zeros at x=3 and 7, the factors of f(x) are:
(x-3)(x-7) so f(x) is
f(x)=x^2-10x+21
