#1)
Answer:
x=1 and y=12
Explanation:
y=5x+7
y=2x+10
This system should use substitution because the value of y is given in terms if x.
Substitution:
5x+7=2x+10
Solve:
3x=3
x=1
Substitute x to solve for y by plugging x into one if the original equations(doesn’t matter which one is used).
y=5x+7
y=5(1)+7
y=5+7
y=12
#2)
Answer:
x=-8 and y=2
Explanation:
y=2x+18
9y=-2x+2
This system also uses substitution. The value of y us already given in terms if c in the first equations, so we will substitute in the second equation.
Substitute:
9(2x+18)=-2x+2
Solve:
18x+162=-2x+2
20x=-160
x=-8
Now that we have the value if x, plug it into one of the original equations(doesn’t matter which equation) and substitute to find y.
y=2x+18
Substitute:
y=2(-8)+18
Solve:
y=-16+18
y=2
Answer:
d. 40 units
Step-by-step explanation:
The length of the horizontal side of this rectangle on the line y=20 is the difference of the x-coordinates, 12 and 20, so is 8. The length of the vertical side on the line x=20 is the difference of the y-coordinates, 20 and 8, so is 12.
Two sides are of length 8 and two are of length 12. The perimeter is the sum of the side lengths, so is ...
P = 2·8 +2·12 = 40 . . . units
Answer:
Step-by-step explanation:
-0.4(3i + 4i) - 0.3(-2i + 5j) + 0.2(-
+ 
j)
-1.2i - 1.6j + 0.6i - 1.5j - 
i + 0.5j
Converting to fraction form;
<u>Solving the i part;</u>
= 
<u>Solving the j part;</u>
j
So -0.4a - o.3b + 0.2d = - 
Car A travels 180miles in 7 hours
Car A travels 25.7 miles an hour because 180/7 = 25.7
Car B travels 350 miles in 4 hours
Car B travels 87.5 miles an hour because 350/4= 87.5
Car C travels 584 miles in 15 hours
Car C travels 38.9 miles an hour because 584/9 = 38.9
Car B has the fastest average speed
