Question
what is the solution to the system of equations?
5x + 4y = 8
x - 2y = 10
(not multiple choice)
my answer: (-5, -1)
What are the missing values? (coincident)
4x + 5y = 8
8x + ____ y = _____
(Not multiple choice)
Im not sure how to do this one
collection of dimes and nickels is worth $6.90. but there are 96 coins all together.. how many coins are there?
______ (not multiple choice) not sure how to do it ..
______
5x + 4y = 8
x - 2y = 10
(not multiple choice)
my answer: (-5, -1)
What are the missing values? (coincident)
4x + 5y = 8
8x + ____ y = _____
(Not multiple choice)
Im not sure how to do this one
collection of dimes and nickels is worth $6.90. but there are 96 coins all together.. how many coins are there?
______ (not multiple choice) not sure how to do it ..
______
Answers
Reiny
#1, you can decide for yourself if (-5,-1) is correct by subbing in those values into both equations.
You should be able to do this mentally.
-- A quick mental calculation shows that your answer does not work in either equation
from the 2nd: x = 2y + 10
plug that into the 1st:
5x + 4y = 8
5(2y+10) + 4y = 8
10y + 50 + 4y = 8
14y = -42
y = -3
then x = 2y+10 = -6+10
= 4
so x = 4, y = -3
2.
Since they are to be coincident, the 2nd equation should be equivalent to the 1st
since 4x was multiplied by 2 to get 8x in the 2nd
do that to the other two terms.
3. d+n = 96 --> n = 96-d
10d + 5n = 690
10d + 5(96-d) = 690
take it from there ....
You should be able to do this mentally.
-- A quick mental calculation shows that your answer does not work in either equation
from the 2nd: x = 2y + 10
plug that into the 1st:
5x + 4y = 8
5(2y+10) + 4y = 8
10y + 50 + 4y = 8
14y = -42
y = -3
then x = 2y+10 = -6+10
= 4
so x = 4, y = -3
2.
Since they are to be coincident, the 2nd equation should be equivalent to the 1st
since 4x was multiplied by 2 to get 8x in the 2nd
do that to the other two terms.
3. d+n = 96 --> n = 96-d
10d + 5n = 690
10d + 5(96-d) = 690
take it from there ....
–24 • 5 = ?
Bot
-120
What is the product of –8 and –7?
Bot
The product of -8 and -7 is 56.
Which of the following has a product of –40?
A. (2)(20)
B. (–4)(–10)
C. (8)(–5)
D. (–7)(60)
A. (2)(20)
B. (–4)(–10)
C. (8)(–5)
D. (–7)(60)
Bot
Option C (8)(-5) has a product of -40.
Which integer represents the total change in altitude of an airplane descending 5 feet every second for 15 seconds?
A. 65
B. 75
C. –75
D. –65
A. 65
B. 75
C. –75
D. –65
Bot
The altitude of the plane is decreasing at a rate of 5 feet per second and it is descending for 15 seconds, therefore the total change in altitude can be found by multiplying 5 by 15 which gives us -75. So, the correct answer is C: -75.
10 • –5 • –4 • 3 = ?
Bot
10 • -5 = -50
-50 • -4 = 200
200 • 3 = 600
Therefore, 10 • –5 • –4 • 3 = 600.
-50 • -4 = 200
200 • 3 = 600
Therefore, 10 • –5 • –4 • 3 = 600.
–64 ÷ 4 = ?
Bot
-64 ÷ 4 = -16
–125 ÷ –5 =
Bot
-125 ÷ -5 = 25
–69 ÷ 3 = ?
Bot
-69 ÷ 3 = -23
What is the quotient of 156 and 12?
Bot
The quotient of 156 and 12 is 13.
What is the quotient of –196 and –7?
Bot
The quotient of -196 and -7 is 28.
What is the quotient of –112 and 2?
Bot
The quotient of -112 and 2 is -56.
Which of the following has a quotient of 5?
Bot
There can be infinite number of possibilities. Could you please provide me with the options for this question?
Which expression has the greatest quotient?
A. –20 ÷ –5
B. 8 ÷ –4
C. –6 ÷ –3
D. 12 ÷ –3
A. –20 ÷ –5
B. 8 ÷ –4
C. –6 ÷ –3
D. 12 ÷ –3
Bot
A. -20 ÷ -5 = 4
B. 8 ÷ -4 = -2
C. -6 ÷ -3 = 2
D. 12 ÷ -3 = -4
Out of these, -2 has the greatest quotient. Thus, option B (8 ÷ –4) has the greatest quotient.
B. 8 ÷ -4 = -2
C. -6 ÷ -3 = 2
D. 12 ÷ -3 = -4
Out of these, -2 has the greatest quotient. Thus, option B (8 ÷ –4) has the greatest quotient.