Answer:
7/20
Step-by-step explanation:
7/10 ÷ 2/1 is the same as 7/10 * 1/2 which is 7/20
Answer:
6. B
7. C
8. B
Step-by-step explanation:
A. Both triangles equal 50 and 10x5 is 50. Therefore, y=5.
Answer:
A book is worth $1 and a DVD is worth $12.
Step-by-step explanation:
The equations (2 unknowns and two equations, d is for a DVD and b is for a book):
For David: 3d+4b=40
For Anna: d+6b=18
Now multiply the second equation with -3 and add to the first equation:
3d+4b=40
−3d−18b=−54
Combined equation: −14b=−14 and b=1 (means that each book is worth $1).
Now for DVD price, use the second equation:
d=18−6 or d=12 (means that each DVD is worth $12).
A book is worth $1 and a DVD is worth $12.
Answer: To determine if two lines are parallel or perpendicular, you have to look at the slopes. For the line y=kx+b, k is the slope.
For two lines y=k1x+b1 and y=k2X+b2 ,When K1=K2, two lines are parallel; when K1=-1/k2, two lines are perpendicular. It doesn't matter whatever b1, b2 are. Hence to save time, you only need to calculate k1 and k2.
To calculate the slope k of any line, you have to change the equation to y=kx+b
For -y=3x-2, k=3/(-1)=-3 (you divide -1 on each side of =, but you don't need to calculate -2/(-1))
For -6X+2y=6, K=6/2=3 (you first move the -6x to right side, it becomes 6x, then divide by 2)
Now you can get the answer: The two lines neither parallel nor perpendicular.
