(x+a)^4 = ^4C_0 x^4 + ^4C_1 x^{4-1} a + ^4C_2x^{4-2}a^2 + ^4C_3x^{4-3}a^3 + ^4C_4x^{4-4}a^4
= x^4 + 4x^3a + 6x^2a^2 + 4xa^3 + a^4
Answer:
The system of inequalities is


Step-by-step explanation:
step 1
Find the equation of the dashed line with negative slope
The line passes through the points
(0,-2) and (-2,0)
Find the slope

Find the equation of the line in slope intercept form

we have

substitute

The solution of the inequality is the shaded area below the dashed line
therefore
The equation of the inequality A is

step 2
Find the equation of the dashed line with positive slope
The line passes through the points
(0,0) and (4,1)
Find the slope

Find the equation of the line (direct variation)

we have

substitute

The solution of the inequality is the shaded area above the dashed line
therefore
The equation of the inequality B is

therefore
The system of inequalities is


Let x represent the number of liters of 50% acid Theresa puts into the mix. The the number of liters of 30% acid will be (420-x). The total amount of acid in the final solution will be ...
0.50x + 0.30(420-x) = 0.45(420)
0.20x + 126 = 189 . . . . . . . . . . . . . . . simplify
0.20x = 63 . . . . . . . . . . . . . . . . . . . . . subtract 126
x = 63/0.20 = 315 . . . . . . . . . . . . . . . liters of 50% solution
(420-x) = 420-315 = 105 . . . . . . . . . liters of 30% solution
Theresa should mix ...
105 liters of 30% solution
315 liters of 50% solution
Answer:
264 I believe
Step-by-step explanation: