For the first one:
m is the slope, or how much the line goes up compared to goes right. In this case, the line goes up 40 every time it goes right 10. We write this as a fraction so 40/10, which simplifies to 4. Therefore the equation would be y = 4x.
Example: 
We can see that there is more than one number with the variable x, therefore, we say they're ''like terms'' and because of that they can be summed. We do this with all of the other numbers with similar variables. If no numbers with similar variables are left, like 4a, you don't do anything but write them as they are. You can also see that 8 and 9 can also be summed because neither of them has a variable, therefore they're similar.
In this step, you just do the operation with the numbers and keep the same variable.
since there are not more numbers similar in variables, this operation is done.
This question is incomplete, the complete question is;
For what value of a is the volume of the tetrahedron formed by the coordinate planes and the plane (x/a) + (y/10) + (z/6) = 1 equal to 10?
Answer: the value of a is 1
Step-by-step explanation:
Given that;
Volume of tetrahedron bounded by plane (x/a) + (y/10) + (z/6) = 1
and coordinate plane is; V = 1/6|abc|
(x/a) + (y/10) + (z/6) = 1
volume = 10
so
10 = 1/6 | a × 10 × 6 |
60 = a × 10 × 6
60 = 60a
a = 60 / 60
a = 1
Therefore the value of a is 1
2x + y = 3
First give them values.
