Let's assume two variables x and y which represent the local and international calls respectively.
x + y = 852 = total number of minutes which were consumed by the company (equation 1)
0.06*x+ 0.15 y =69.84 = total price which was charged for the phone calls (Equation 2)
from equation 1:-
x=852 -y (sub in equation 2)
0.06 (852 - y) + 0.15 y =69.84
51.12 -0.06 y +0.15 y =69.84 (subtracting both sides by 51.12)
0.09 y =18.74
y= 208 minutes = international minutes (sub in 1)
208+x=852 (By subtracting both sides by 208)
x = 852-208 = 644 minutes = local minutes
Answer:
C
Step-by-step explanation:
A, B are wrong since 8,795 is a constant, it doesn’t change;
D is wrong since it is the starting cost, not total cost
Answer:
20 pencils
Step-by-step explanation:
4 pens (4) = 16 pens
5 pencils (4) = 20 pencils
This works because 4/5 and 16/20 are the same ratio, 16/20 isn't simplified..
Answer:
A, B
Step-by-step explanation:
After being simplified and put in standard form, the equations are ...
A. 3x² +8x -13 = 0 . . . a quadratic
B. 3x² -x -30 = 0 . . . . a quadratic
C. 4x = -16 . . . . . . . . . a linear equation, not quadratic
D. 3x⁴ -5x -6 = 0 . . . . a quartic equation, not quadratic
Both of the quadratic equations can be solved using the quadratic formula.