Answer:
y = 3/4 or y = -3/5
Step-by-step explanation:
Solve for y:
(8 y - 6) (10 y + 6) = 0
Hint: | Find the roots of each term in the product separately.
Split into two equations:
8 y - 6 = 0 or 10 y + 6 = 0
Hint: | Look at the first equation: Factor the left hand side.
Factor constant terms from the left hand side:
2 (4 y - 3) = 0 or 10 y + 6 = 0
Hint: | Divide both sides by a constant to simplify the equation.
Divide both sides by 2:
4 y - 3 = 0 or 10 y + 6 = 0
Hint: | Isolate terms with y to the left hand side.
Add 3 to both sides:
4 y = 3 or 10 y + 6 = 0
Hint: | Solve for y.
Divide both sides by 4:
y = 3/4 or 10 y + 6 = 0
Hint: | Look at the second equation: Factor the left hand side.
Factor constant terms from the left hand side:
y = 3/4 or 2 (5 y + 3) = 0
Hint: | Divide both sides by a constant to simplify the equation.
Divide both sides by 2:
y = 3/4 or 5 y + 3 = 0
Hint: | Isolate terms with y to the left hand side.
Subtract 3 from both sides:
y = 3/4 or 5 y = -3
Hint: | Solve for y.
Divide both sides by 5:
Answer: y = 3/4 or y = -3/5
Number of weekend minutes used: x
Number of weekday minutes used: y
This month Nick was billed for 643 minutes:
(1) x+y=643
The charge for these minutes was $35.44
Telephone company charges $0.04 per minute for weekend calls (x)
and $0.08 per minute for calls made on weekdays (y)
(2) 0.04x+0.08y=35.44
We have a system of 2 equations and 2 unkowns:
(1) x+y=643
(2) 0.04x+0.08y=35.44
Using the method of substitution
Isolating x from the first equation:
(1) x+y-y=643-y
(3) x=643-y
Replacing x by 643-y in the second equation
(2) 0.04x+0.08y=35.44
0.04(643-y)+0.08y=35.44
25.72-0.04y+0.08y=35.44
0.04y+25.72=35.44
Solving for y:
0.04y+25.72-25.72=35.44-25.72
0.04y=9.72
Dividing both sides of the equation by 0.04:
0.04y/0.04=9.72/0.04
y=243
Replacing y by 243 in the equation (3)
(3) x=643-y
x=643-243
x=400
Answers:
The number of weekends minutes used was 400
The number of weekdays minutes used was 243
Answer:
square root of 125 rounded to 11.2 milies to the nearest tenth
