Ok so if you notice every choice is solved for a, all you have to do is isolate "a" in 7a-8b=10x. Start by moving 8b to the other side and to change the sign. Now it is 7a = 10x + 8b. Then divide everything by 7 and you get a = (10x + 8b)/7
Answer: 38 over 49 can be written as 38/49. When divided, you will get 0.77551020408. It takes lots of regrouping, but it ends eventually.
If you are reducing it as a fraction, it is not possible because there is no other number to reduce it, so it will be in it's simplest form already.
Answer:
The solution is (-2,4)
Step-by-step explanation:
We'll solve the system
2x+5y=16
-5x-2y=2
using elimination by addition and subtraction.
Let's eliminate x first. To do this, multiply the first equation by 5 and multiply the second equation by 2. We get:
10x + 25y = 80
-10x - 4y = 4
----------------------
21y = 84. Thus, y = 84/21 = 4.
Subbing 4 for y in the second equation, we get
-5x -2(4) = 2, or
-8 - 2 = 5x, or
-10 = 5x. Thus, x = -10/5 = -2.
The solution is (-2,4)
First piece is x
second piece is y. y=4x
third piece is z. z=3y=12x
x+y+z=680
x+4x+12x=680
17x=680. x=40cm y=160cm. z=480cm
