Answer:
a = 3, b = -1, c = 10
Step-by-step explanation:
Let the three numbers be a, b and c.
Equation 1: a + b + c = 12
Equation 2: a + 2b + 3c = 31
Equation 3: 9b + c = 1
Equation 2 - Equation 1:
Equation 4: b + 2c = 19
Equation 3 times by the number 2
Equation 5: 18b + 2c = 2
Equation 5 - Equation 4
17b = -17
b = -1
Substitute into Equation 4:
2c - 1 = 19
2c = 20
c = 10
Substitute into Equation 1:
a + b + c = 12
a - 1 + 10 = 12
a = 3
Answer:
The ride took 7 1/2 hours to complete.
Step-by-step explanation:
If the bicyclist is going at a constant speed of 6mi/hr it would take 7 1/2 hours to ride 45 miles.
6*7 1/2=45
Answer:
expression: 3(d+35)
simplified expression: 3d + 105
Step-by-step explanation:
The first drone costs d. This means the expression = d
The second drone costs d and an additional $35. Expression = d + 35
The third drone costs 3 times as much as the previous one. Expression = 3(d+35)
To simplify it, you just distribute. Hope this helps :)
Answer:
y = (5/4)x + 6
Step-by-step explanation:
The 1st line's equation is:
● 4x + 5y = 20
Substract 4x from both sides
● 4x + 5y - 4x = 20 - 4x
● 5y = 20 -4x
● 5y = -4x + 20
Divide both sides by 5
● 5y/5 = (-4x + 20)/5
● y = (-4/5)x + 4
● y = -0.8x + 4
Let m be the slope of the second line
The lines are perpendicular so the product of their slopes equals -1
Then: m × (-0.8) = -1
● m × (-0.8)= -1
● m = -1/(-0.8)
● m = 1.25
y = 1.25x + b
b is the y-intercept of the line.
To get it replace by the coordinates of a point.
We are given that the line passes through (-4,1)
● y = 1.25x + b
● 1 = 1.25 × (-4) + b
1.25 is 5/5
● 1 = (5/4) × (-4) + b
● 1 = -5 + b
Add 5 to both sides
● 1 + 5 = -5 + b + 5
● b = 6
So the equation is
● y = (5/4)x + 6
1st disribute .4 through the parentheses.
.4 (.3x-1)=2+.75x
.12x-.4=2+.75x
subtract .12x from each side
-.4 = 2 + .63x
subtract 2 from each side
-2.4 = .63x
Divide each side by .63
-3.81 = x
