Answer:
Step-by-step explanation:
Question 1
System of equations is,
y = -6x -------(1)
y = -4x - 2 ---------(2)
Substitute the value of y from equation (1) to equation (2)
-6x = -4x - 2
-6x + 4x = -2
-2x = -2
x = 1
From equation (1)
y = -6(1)
y = -6
Question (2)
System of equations is,
-y = x --------(1)
3x + 5y = 20 ---------(2)
Substitute the value of x from equation (1) to equation (2)
3(-y) + 5y = 20
-3y + 5y = 20
2y = 20
y = 10
From equation (1)
-y = x
x = -10
Question (3)
System of the equations is,
y = -2x - 7 --------(1)
9x - 10y = 12 ----------(2)
Substitute the value of y from equation (1) to equation (2)
9x - 10(-2x - 7) = 12
9x + 20x + 70 = 12
29x = 12 - 70
29x = -58
x = -2
From equation (1)
y = -2(-2) - 7
y = 4 - 7
y = -3
Answer:
mph per minute
Step-by-step explanation:
It would be mph per minute. This is due to the fact that it already measuring the speed (miles per minute) but it is solving for how this changes per minute, therefore mph per minute.
Answer: x = 28
Step-by-step explanation:
x + 20=3x-36
20=2x-36
56=2x
56/2=28
So 28= x
Answer:
37 1/4 (answer)
Step-by-step explanation:
One way of approaching this problem would be to rewrite each proper fraction as a decimal fraction:
6.75
+7.25
+8.25
+7.25
+7.75
-----------
This comes out to 14 + 15.5 + 7.75, or
29.5 + 7.75, or
36.0 + 1.25, or 37.25. This is the same as 37 1/4 (answer)
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