Answer: chicken $8, duck $5
Explanation:
x - the cost of a chicken
y - the cost of a duck
he sold 50 chickens and 30 ducks for $550: 50x + 30y = 550
he sold 44 chickens and 36 ducks for $532: 44x + 36y = 532
50x + 30y = 550 divide by 10
44x + 36y = 550 divide by 4
______________
50x/10 + 30y/10 = 550/10
44x/4 + 36y/4 = 532/4
______________
5x + 3y = 55
Multiply by (-3)
11x + 9y = 133
______________
5x * (-3) + 3y * (-3) = 55 * (-3)
11x + 9y = 133
______________
-15x - 9y = -165
11x + 9y = 133
______________
Sum up:
-4x + 0y = -32
-4x = -32
x = -32/-4
x = 8
Since 5x + 3y = 55 and x = 8, then:
5 * 8 + 3y = 55
40 + 3y = 55
3y = 55 - 40
3y = 15
y = 15/3
y = 5
Step-by-step explanation:
0.6m×0.8
=0.48m²
is like this?
hope it help
Answer:
Step-by-step explanation:
20.1metres / seconds
We want to convert to metres /minutes
It is known that 60seconds=1minutes
So therefore, either we multiply 20.1metres/seconds by
60seconds/1minutes
Or
1minutes/60seconds
Multiplying with the above does not change the magnitude of the quantity because it is like we are multiplying by 1.
Since we want to cancel seconds and it is in the denominator, so to do this we need to multiply with the fraction that has the seconds as numerator.
So, we are going to multiply with 60seconds/1minutes
20.1metres/seconds ×60seconds/minutes
1206metres/minutes.
So the correct fraction is the StartFraction 60 seconds Over 1 minute, which is the third option
Answer:
Natalia's work is wrong.
Step-by-step explanation:
Natalia divided a decimal number by an entire number. Since division is a operation derived from multiplication, the best approach to check if work was good is multiplying the given result by denomination, that is:
1) 
Given.
2) 
Definition of addition.
3) 
Distributive property.
4) 
Definitions of multiplication and decimal number.
5) ![x = 72 +[2\cdot (10)^{-1}]\cdot 12](https://tex.z-dn.net/?f=x%20%3D%2072%20%2B%5B2%5Ccdot%20%2810%29%5E%7B-1%7D%5D%5Ccdot%2012)
Definition of division/Associative property.
6) ![x = 72 + [2\cdot 12]\cdot (10)^{-1}](https://tex.z-dn.net/?f=x%20%3D%2072%20%2B%20%5B2%5Ccdot%2012%5D%5Ccdot%20%2810%29%5E%7B-1%7D)
Associative property.
7) 
Definition of multiplication.
8) 
Definition of divsion.
9) 
Defintion of decimal number.
10) 
Definition of addition/Result
Natalia's work is wrong.
